Opioid modulation of immune responses: effects on phagocyte and lymphoid cell populations

Nanotechnology-Enhanced Naloxone and Alternative Treatments for Opioid Addiction

Opioids are commonly prescribed to address intense, ongoing pain associated with cancer, as well as long-lasting noncancer-related pain when alternative methods have proven ineffective. Individuals who exhibit both chronic pain and misuse of opioids face a significant danger of experiencing adverse health outcomes and the potential loss of life related to opioid use. Thus, there is a current movement to prescribe naloxone to those considered high-risk for opioid overdose. Naloxone has been explored as an antidote to reverse acute respiratory depression. Conversely, naloxone can give rise to other problems, including hypertension and cardiac arrhythmias. Thus, the importance of nanotechnology-enabled drug delivery strategies and their role in mitigating naloxone side-effects are significant. In this review, we explore the latest advancements in nanotechnology-enabled naloxone and alternative methods for addressing the opioid crisis through the utilization of non-opioid natural alternatives for chronic pain management.

Impact of spinal or epidural anaesthesia on perioperative outcomes in adult noncardiac surgery: a narrative review of recent evidence

Spinal and epidural anaesthesia and analgesia are important anaesthetic techniques, familiar to all anaesthetists and applied to patients undergoing a range of surgical procedures. Although the immediate effects of a well-conducted neuraxial technique on nociceptive and sympathetic pathways are readily observable in clinical practice, the impact of such techniques on patient-centred perioperative outcomes remains an area of uncertainty and active research. The aim of this review is to present a narrative synthesis of contemporary clinical science on this topic from the most recent 5-year period and summarise the foundational scholarship upon which this research was based. We searched electronic databases for primary research, secondary research, opinion pieces, and guidelines reporting the relationship between neuraxial procedures and standardised perioperative outcomes over the period 2018-2023. Returned citation lists were examined seeking additional studies to contextualise our narrative synthesis of results. Articles were retrieved encompassing the following outcome domains: patient comfort, renal, sepsis and infection, postoperative cancer, cardiovascular, and pulmonary and mortality outcomes. Convincing evidence of the beneficial effect of epidural analgesia on patient comfort after major open thoracoabdominal surgery outcomes was identified. Recent evidence of benefit in the prevention of pulmonary complications and mortality was identified. Despite mechanistic plausibility and supportive observational evidence, there is less certain experimental evidence to support a role for neuraxial techniques impacting on other outcome domains. Evidence of positive impact of neuraxial techniques is best established for the domains of patient comfort, pulmonary complications, and mortality, particularly in the setting of major open thoracoabdominal surgery. Recent evidence does not strongly support a significant impact of neuraxial techniques on cancer, renal, infection, or cardiovascular outcomes after noncardiac surgery in most patient groups.

Progress in the study of intestinal microbiota involved in morphine tolerance

Morphine is a widely used opioid for treatment of pain. The attendant problems including morphine tolerance and morphine dependence pose a major public health challenge. In recent years, there has been increasing interest in the gastrointestinal microbiota in many physiological and pathophysiological processes. The connectivity network between the gut microbiota and the brain is involved in multiple biological systems, and bidirectional communication between them is critical in gastrointestinal tract homeostasis, the central nervous system, and the microbial system. Many research have previously shown that morphine has a variety of effects on the gastrointestinal tract, but none have determined the function of intestinal microbiota in morphine tolerance. This study reviewed the mechanisms of morphine tolerance from the perspective of dysregulation of microbiota-gut-brain axis homeostasis, by summarizing the possible mechanisms originating from the gut that may affect morphine tolerance and the improvement of morphine tolerance through the gut microbiota.

Heroin Use Is Associated With Vascular Inflammation in Human Immunodeficiency Virus

BACKGROUND

Heroin use may work synergistically with human immunodeficiency virus (HIV) infection to cause greater immune dysregulation than either factor alone. Unraveling how this affects end-organ disease is key as it may play a role in the excess mortality seen in people with HIV (PWH) who use heroin despite access to care and antiretroviral therapy.

METHODS

This is a prospectively enrolled, cross-sectional study of adults with and without HIV who use and do not use heroin using (18)F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) to compare tissue-specific inflammation including aortic (target-to-background ratio [TBR]), splenic, and bone marrow (standardized uptake value [SUV]).

RESULTS

A total of 120 participants were enrolled. The unadjusted mean difference in aortic TBR was 0.43 between HIV-positive [HIV+] heroin+ and HIV+ heroin-negative [heroin-] (P = .02); however, among HIV-, aortic TBR was similar regardless of heroin-use status. Further, HIV-by-heroin-use status interaction was significant (P = .02), indicating that the relationship between heroin use and higher aortic TBR depended on HIV status. On the other hand, both HIV (1.54 vs 1.68; P = .04, unadjusted estimated means for HIV+ vs HIV-) and heroin use were associated with lower bone marrow SUV, although the effect of heroin depended on sex (heroin-use-by-sex interaction, P = .03). HIV-by-heroin-use interaction was not significant for splenic or bone marrow SUV.

CONCLUSIONS

Aortic inflammation was greatest in PWH who use heroin, but paradoxically, bone marrow activity was the least in this group, suggesting complex and possibly divergent pathophysiology within these different end organs.

Knowledge Mapping of Opioids and Immunomodulation: A Bibliometric Analysis (2000-2022)

Background

Increasing evidence indicates that opioids markedly affect the immune system. However, there are few studies on opioids and immunomodulation using bibliometric analysis.

Purpose

We aimed to provide a comprehensive overview of the research status and trends of the influence of opioids on immunomodulation using a bibliometric approach.

Methods

Articles related to opioids and immunomodulation published from 2000 to 2022 were obtained from the Science Citation Index Expanded of the Web of Science Core Collection by searching keywords related to opioids and immunomodulation. Bibliometric analyses and visualizations were conducted using the CiteSpace and VOSviewer software programs.

Results

From 2000 to 2022, a total of 3242 research articles on opioids and immunomodulation were published in 1126 academic journals by 16,555 authors in 3368 institutions from 102 countries/regions. A majority of publications were from the US and China, and the University of Minnesota System and Chinese Academy of Sciences were the most active institutions. Tsong-long Hwang had published the most papers, while Sabita Roy had the most cocitations. The Journal of Ethnopharmacology published the most papers on opioids and immunomodulation, the Journal of Immunology was the top cocited journal, and the major area of these publications were molecular, biological, and genetic. The top three keywords were "expression", "activation", and "inflammation."

Conclusion

The number of studies on opioids and immunomodulation has increased sharply all over the world in the last two decades. This is the first bibliometric study to comprehensively summarize the collaboration network in this field. It will help scholars to understand not only the basic knowledge structure but also potential collaborations, research trend topics, and hot directions.

A new S. suis serotype 3 infection model in pigs: lack of effect of buprenorphine treatment to reduce distress

BACKGROUND

Streptoccocus suis (S. suis) is a major porcine pathogen causing meningitis, septicemia, arthritis and endocarditis. These diseases severely impair welfare of pigs. Experimental studies in pigs are important to better understand the pathogenesis and to identify protective antigens, as so far there is no vaccine available protecting against various serotypes (cps). Due to the severity of disease, application of appropriate refinement strategies in experimental S. suis infections is essential to reduce distress imposed on the piglets without jeopardizing the scientific output. The objectives of this study were to evaluate buprenorphine treatment as a refinement measure and serum cortisol levels as a distress read out parameter in a new S. suis cps3 infection model in pigs.

RESULTS

Intravenous application of 2 × 10⁸ CFU of S. suis cps3 (sly⁺, mrp⁺) to 6-week-old piglets led to severe morbidity in approximately 50% of the animals. Main pathological findings included suppurative meningoencephalitis and arthritis as well as fibrinosuppurative endocarditis. Buprenorphine treatment (0.05 mg/kg every 8 h) did not prevent signs of severe pain, high clinical scores, moderate to severe pathologies or high levels of serum cortisol in single severely affected piglets. Significant differences in the course of leukocytosis, induction of specific antibodies and bactericidal immunity were not recorded between groups with or w/o buprenorphine treatment. Of note, clinically unobtrusive piglets showed serum cortisol levels at 2 and 5 days post infectionem (dpi) comparable to the levels prior to infection with cps3. Cortisol levels in serum were significantly increased in piglets euthanized due to severe disease in comparison to clinically unobtrusive pigs.

CONCLUSIONS

Different clinical courses and pathologies are induced after intravenous challenge of piglets with 2 × 10⁸ CFU of this S. suis cps3 strain. The chosen protocol of buprenorphine application does not prevent severe distress in this infection model. Important parameters of the humoral immune response, such as the level of IgM binding to S. suis cps3, do not appear to be affected by buprenorphine treatment. Serum cortisol is a meaningful parameter to measure distress in piglets experimentally infected with S. suis and to evaluate refinement strategies. In this intravenous model, which includes close clinical monitoring and different humane endpoints, clinics and cortisol levels suggest convalescence in surviving piglets within 5 days following experimental infection.

Opioids Regulate the Immune System: Focusing on Macrophages and Their Organelles

Opioids are the most widely used analgesics and therefore have often been the focus of pharmacological research. Macrophages are the most plastic cells in the hematopoietic system. They show great functional diversity in various organism tissues and are an important consideration for the study of phagocytosis, cellular immunity, and molecular immunology. The expression of opioid receptors in macrophages indicates that opioid drugs act on macrophages and regulate their functions. This article reviewed the collection of research on effects of opioids on macrophage function. Studies show that opioids, both endogenous and exogenous, can affect the function of macrophages, effecting their proliferation, chemotaxis, transport, phagocytosis, expression of cytokines and chemokine receptors, synthesis and secretion of cytokines, polarization, and apoptosis. Many of these effects are closely associated with mitochondrial function and functions of other organelles in macrophages. Therefore, in depth research into effects of opioids on macrophage organelles may lead to some interesting new discoveries. In view of the important role of macrophages in HIV infection and tumor progression, this review also discusses effects of opioids on macrophages in these two pathological conditions.

Effect of pregabalin on nociceptive thresholds and immune responses in a mouse model of incisional pain

Background

It is known that some analgesics as well as pain can affect the immune system. The aim of this study was to investigate the analgesic effect and immunomodulation of pregabalin (PGB) in a mouse incisional pain model.

Methods

A postoperative pain model was induced by hind paw plantar incision in male BALB/c mice. Mice were randomly divided into four groups (n = 8) a saline-treated incision (incision), PGB-treated incision (PGB-incision), sham controls without incision or drug treatment (control), and a PGB-treated control (PGB-control). In the PGB treated groups, PGB was administered intraperitoneally (IP) 30 minutes before and 1 hour after the plantar incision. Changes of the mechanical nociceptive thresholds following incision were investigated. Mice were euthanized for spleen harvesting 12 hours after the plantar incision, and natural killer (NK) cytotoxicity to YAC 1 cells and lymphocyte proliferation responses to phytohemagglutinin were compared among these four groups.

Results

Mechanical nociceptive thresholds were decreased after plantar incision and IP PGB administration recovered these decreased mechanical nociceptive thresholds (P < 0.001). NK activity was increased by foot incision, but NK activity in the PGB-incision group was significantly lower than that in the Incision group (P < 0.001). Incisional pain increased splenic lymphocyte proliferation, but PGB did not alter this response.

Conclusions

Incisional pain alters cell immunity of the spleen in BALB/c mice. PGB showed antinocieptive effect on mouse incisional pain and attenuates the activation of NK cells in this painful condition. These results suggest that PGB treatment prevents increases in pain induced NK cell activity.

Morphine-3-glucuronide upregulates PD-L1 expression via TLR4 and promotes the immune escape of non-small cell lung cancer

Objective

Patients with cancer pain are highly dependent on morphine analgesia, but studies have shown a negative correlation between morphine demand and patient outcomes. The long-term use of morphine may result in abnormally elevated serum morphine-3-glucuronide (M3G) levels. Hence, the effects of M3G on tumor progression are worth studying.

Methods

The effects of M3G on PD-L1 expressions in human non-small cell lung cancer (NSCLC) cell lines were first evaluated. Activation of TLR4 downstream pathways after M3G treatment was then determined by Western blot. The effects of M3G on human cytotoxic T lymphocytes (CTL) cytotoxicity and INF-γ release was also detected. Finally, the LLC murine lung adenocarcinoma cell line were used to establish a murine lung cancer model, and the effects of M3G on tumor growth and metastasis were determined.

Results

M3G promoted the expressions of PD-L1 in the A549 and H1299 cell lines in a TLR4-dependent manner (P < 0.05). M3G activated the PI3K and the NFκB signaling pathways, and this effect was antagonized by a TLR4 pathway inhibitor. A PI3K pathway inhibitor reversed the M3G-mediated PD-L1 upregulation. M3G inhibited the cytotoxicity of CTL on A549 cells and decreased the level of INF-γ. Repeated M3G intraperitoneal injections promoted LLC tumor growth and lung metastasis through the upregulation of tumor expressed PD-L1 and the reduction of CTL in the tumor microenvironment.

Conclusions

M3G specifically activated TLR4 in NSCLC cells and upregulated PD-L1 expression through the PI3K signaling pathway, thereby inhibiting CTL cytotoxicity and finally promoting tumor immune escape.

Biomarkers to predict staging and treatment response in opioid dependence: A narrative review

Opioid use disorder is a devastating disorder with a high burden in terms of overdose mortality, with an urgent need for more personalized prevention or therapeutic interventions. For this purpose, the description and validation of biological measures of staging or treatment response is a highly active research field. We conducted a narrative review on the pathophysiology of opioid use disorder to propose staging of the disease and search for research studies proposing or demonstrating the predictive value of biomarkers. We propose a IV stage description of opioid use disorder, from (I) vulnerability stage to (II) disease progression, (III) constituted opioid dependence and were several type of treatments can be applied, to the reach a (IV) modified health state. We classified biomarkers studies according to the stage of the disorder they were intended to predict, and to the three categories of methods they used: anatomical and functional aspects of the brain, genetic/transcriptomic/epigenetic studies, and lastly biomarkers of systemic modifications associated with opioid use disorder, especially regarding the immune system. Most studies predicting Stage III that we reviewed collected data from small samples sizes and were cross-sectional association studies comparing opioid dependent patients and control groups. Pharmacogenetic biomarkers are proposed to predict treatment response. Future research should now emphasize prospective studies, replication in independent samples, and predictive value calculation of each biomarker. The most promising results are multimodal evaluations to be able to measure the state of the brain reward system in living individuals.

The association of prescription opioid use with incident cancer: A Surveillance, Epidemiology, and End Results-Medicare population-based case-control study

BACKGROUND

Cancer is the second leading cause of death globally, and researchers seek to identify modifiable risk factors Over the past several decades, there has been ongoing debate whether opioids are associated with cancer development, metastasis, or recurrence. Basic science, clinical, and observational studies have produced conflicting results. The authors examined the association between prescription opioids and incident cancers using the Surveillance, Epidemiology, and End Results (SEER)-Medicare database. A complex relation was observed between prescription opioids and incident cancer, and cancer site may be an important determinant.

METHODS

By using linked SEER cancer registry and Medicare claims from 2008 through 2013, a case-control study was conducted examining the relation between cancer onset and prior opioid exposure. Logistic regression was used to account for differences between cases and controls for 10 cancer sites.

RESULTS

Of the population studied (n = 348,319), 34% were prescribed opioids, 79.5% were white, 36.9% were dually eligible (for both Medicare and Medicaid), 13% lived in a rural area, 52.7% had ≥1 comorbidity, and 16% had a smoking-related diagnosis. Patients exposed to opioids had a lower odds ratio (OR) associated with breast cancer (adjusted OR, 0.96; 95% CI, 0.92-0.99) and colon cancer (adjusted OR, 0.90; 95% CI, 0.86-0.93) compared with controls. Higher ORs for kidney cancer, leukemia, liver cancer, lung cancer, and lymphoma, ranging from lung cancer (OR, 1.04; 95% CI, 1.01-1.07) to liver cancer (OR, 1.19; 95% CI, 1.08-1.31), were present in the exposed population.

CONCLUSIONS

The current results suggest that an association exists between prescription opioids and incident cancer and that cancer site may play an important role. These findings can direct future research on specific patient populations that may benefit or be harmed by prescription opioid exposure.

Persons who inject drugs (PWID) retain functional NK cells, dendritic cell stimulation, and adaptive immune recall responses despite prolonged opioid use

Previous literature suggests that acute opioid use results in the functional impairment of the immune response, thereby decreasing resistance to viral infection. Here, we assessed if innate and adaptive immune responses are compromised ex vivo in persons who inject drugs (PWID) and whether long-term injection drug use may impact host susceptibility to in vitro HIV infection. We measured the frequency, activation state, and functional profile of NK cells, dendritic cells, and CD4+ and CD8+ T cells in low-risk PWID who do not share needles, high-risk needle-sharing PWID, and control donors who did not inject drugs. We also assessed plasma levels of inflammatory markers and CD4+ T cell susceptibility to HIV infection. We observed a significant increase in the amount of sCD14 (P = 0.0023, n = 16) and sCD163 (P = 0.0001, n = 16) in the plasma of PWID compared to controls. Evidence of constitutive activation was noted in PWID as compared to controls with increased CD69 expression in CD56dim NK cells (P = 0.0103, n = 26) and increased CD38 and HLA-DR expression in CD4+ T cells (P = 0.0355, n = 23). However, no innate or adaptive functional differences were detected between PWID and controls, including: NK cell direct or antibody-dependent cellular cytotoxicity poly-functional response, TLR-stimulated dendritic cell/NK crosstalk, CD8+ T cell response to Staphylococcal enterotoxin B or CMV/EBV/FLU peptides, or constitutive or anti-CD3/CD28-stimulated CD4+ T cell infectivity with CCR5-tropic or CXCR4-tropic HIV-1 isolates. Our data indicate that PWID who utilize opioids over as prolonged time frame can retain a functional ex vivo immune response without a measurable increase in CD4+ T cell infectivity suggesting that leukocytes from PWID are not intrinsically more susceptibility to infection with HIV than non-PWID controls.

The Effects of Chronic Preoperative Opioid Use on Single-level Lumbar Fusion Outcomes

STUDY DESIGN

A retrospective study using a national insurance claims database.

OBJECTIVE

The objective of this study was to assess the relationship between chronic preoperative opioids and the outcomes of revision surgery and nonunion after single-level lumbar fusion.

SUMMARY OF BACKGROUND DATA

Opioids are widely utilized for pain management before spine procedures. Studies have associated opioids with unfavorable postoperative outcomes, and animal models have also linked opioid administration with unstable bone healing.

METHODS

Single-level lumbar fusion patients were identified. Patients with any fracture history within 1 year before surgery were excluded. A chronic preoperative opioid cohort was defined by opioids prescriptions within 3 months prior and within 4-6 months before surgery. The rates of revision surgery within 6 months and nonunion within 6-24 months after surgery were assessed. Univariate analyses of chronic preoperative opioid prescriptions and various comorbidities for revision and nonunion were conducted followed by multivariate analyses controlling for these factors. Individual analyses were run for each of the 3 single-level lumbar fusion procedures.

RESULTS

A total of 8494 single-level lumbar fusion patients were identified. Of the 3929 (46.3%) patients filled criteria for the chronic preoperative opioid cohort, while 3250 (38.3%) patients had no opioid prescriptions within 6 months before surgery. The opioid cohort experienced significantly higher rates of both revisions (3.92% vs. 2.71%, P=0.005) and nonunion (3.84% vs. 2.89%, P=0.027) relative to the opioid-naive cohort. In the multivariate analyses, chronic preoperative opioids were identified as an independent risk factor for revision (odds ratio: 1.453, P=0.006).

CONCLUSIONS

We report that chronic opioid prescriptions before lumbar fusion may increase the risk of revision. Although these prescriptions were also associated with increased nonunion, the comparisons did not achieve statistical significance in the multivariate model. Chronic preoperative opioid use may be considered a potential risk factor in arthrodesis populations.

Thyroid cancer in the Era of COVID-19

The recent coronavirus infectious disease (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is placing health systems in serious challenges worldwide. Shocking statistics each day has prompted the World Health Organization to officially declare the COVID-19 outbreak as a pandemic in March 2020. Preliminary studies have shown increased mortality in patients with solid cancers and infection by SARS-CoV-2. Until now, the evidence on the behavior of COVID-19 in patients with a history of thyroid cancer remains scarce, and most of the recommendations given are based on common sense. Therefore, in this viewpoint, we present a brief review of several challenges we are frequently facing during this pandemic and a series of recommendations based on what we have implemented in our clinical practice at a university hospital currently mostly dedicated to COVID-19.

A randomized pilot study to investigate the effect of opioids on immunomarkers using gene expression profiling during surgery

Endogenous opioid peptides and exogenous opioids modulate immune function, and animal and human studies have shown that some have a depressant immunomodulatory effect. This is potentially of high clinical significance, eg, in cancer patients and surgery. The primary objective of this pilot study was to evaluate the effect of morphine and oxycodone on immune pathways associated with immunosuppression in gynecological laparotomy patients. Gene expression was analyzed in CD4, CD8, and natural killer (NK) cells using the 3' Affymetrix microarray. Patients were randomized to receive morphine, oxycodone, or nonopioid "control" analgesia during and after surgery. Genes demonstrating differential expression were those with a ≥±2-fold difference and P-value ≤0.05 after analysis of variance. Cytometric bead array and NK cell degranulation assay were used to investigate changes in serum cytokine concentration and in NK cell cytotoxicity, respectively. Forty patients had satisfactory RNA which was hybridized to gene chips. Genes were identified (Partek Genomics Suite 6.6) at baseline, 2, 6, and 24 hours and were either ≥2-fold upregulated or downregulated from baseline. At 2 hours, a large number of genes were downregulated with morphine but not with control analgesia or oxycodone. Statistically significant increases in IL-6 concentrations were induced by morphine only; NK cell activity was suppressed with morphine, but maintained with oxycodone and epidural analgesia. Gene expression profiles suggest that at 2 hours, post incision morphine appeared to be immunosuppressive as compared to oxycodone and nonopioid control analgesia.

Etiology, clinical presentation, outcome and the effect of initial management in immunocompromised patients with community acquired bacterial meningitis

OBJECTIVES

The aim was to analyze differences in clinical presentation, etiology, management, and outcome between immunocompromised and immunocompetent patients with acute bacterial meningitis (ABM).

METHODS

Data were extracted from 1056 adult ABM patients prospectively registered in the national Swedish quality register for ABM during 2008-2017. Primary endpoint was 30-day mortality and secondary endpoints 90-day mortality and unfavorable outcome.

RESULTS

An immunocompromised state was observed in 352 (33%) of the 1056 patients. Streptococcus pneumoniae dominated in both immunocompromised and immunocompetent patients (53% in both groups), whereas L monocytogenes occurred in 11% and 2%, respectively. The unadjusted odds ratio (OR) for 30-day mortality in immunocompromised compared to immunocompetent patients was 1.68 (95% confidence interval (CI): 1.07-2.63). Adjusted for age, sex, and mental status on admission the OR was 1.34 (CI: 0.82-2.21). Adjusted also for time to antibiotic treatment and corticosteroids the OR was 1.10 (CI: 0.59-2.05), and in patients without Listeria meningitis 0.98 (CI: 0.50-1.90). Although, the ORs were higher for 90-day mortality and unfavorable outcome the effects of adjustments were similar.

CONCLUSION

Mortality in immunocompromised patients with ABM is only moderately increased unless caused by Listeria. This difference is further reduced in patients given early antibiotic treatment and adjunctive corticosteroids.

FUNDING

This work was supported by Stockholm County Council.

Influence of postoperative analgesia on systemic inflammatory response and postoperative cognitive dysfunction after femoral fractures surgery: a randomized controlled trial

BACKGROUND AND OBJECTIVES

To investigate the possible effect of postoperatively applied analgesics-epidurally applied levobupivacaine or intravenously applied morphine-on systemic inflammatory response and plasma concentration of interleukin (IL)-6 and to determine whether the intensity of inflammatory response is related to postoperative cognitive dysfunction (POCD).

METHODS

This is a randomized, prospective, controlled study in an academic hospital. Patients were 65 years and older scheduled for femoral fracture fixation from July 2016 to September 2017. Inflammatory response was assessed by leukocytes, neutrophils, C reactive protein (CRP) and fibrinogen levels in four blood samples (before anesthesia, 24 hours, 72 hours and 120 hours postoperatively) and IL-6 concentration from three blood samples (before anesthesia, 24 hours and 72 hours postoperatively). Cognitive function was assessed using the Mini-Mental State Examination preoperatively, from the first to the fifth postoperative day and on the day of discharge.

RESULTS

The study population included 70 patients, 35 in each group. The incidence of POCD was significantly lower in the levobupivacaine group (9%) than in the morphine group (31%) (p=0.03). CRP was significantly lower in the levobupivacaine group 72 hours (p=0.03) and 120 hours (p=0.04) after surgery. IL-6 values were significantly lower in the levobupivacaine group 72 hours after surgery (p=0.02). The only predictor of POCD in all patients was the level of IL-6 72 hours after surgery (p=0.03).

CONCLUSIONS

There is a statistically significant association between use of epidural levobupivacaine and a reduction in some inflammatory markers. Postoperative patient-controlled epidural analgesia reduces the incidence of POCD compared with intravenous morphine analgesia in the studied population.

TRIAL REGISTRATION NUMBER

NCT02848599.

The Role of Opioid Receptors in Immune System Function

Research on the effects of opioids on immune responses was stimulated in the 1980s by the intersection of use of intravenous heroin and HIV infection, to determine if opioids were enhancing HIV progression. The majority of experiments administering opioid alkaloids (morphine and heroin) in vivo, or adding these drugs to cell cultures in vitro, showed that they were immunosuppressive. Immunosuppression was reported as down-regulation: of Natural Killer cell activity; of responses of T and B cells to mitogens; of antibody formation in vivo and in vitro; of depression of phagocytic and microbicidal activity of neutrophils and macrophages; of cytokine and chemokine production by macrophages, microglia, and astrocytes; by sensitization to various infections using animal models; and by enhanced replication of HIV in vitro. The specificity of the receptor involved in the immunosuppression was shown to be the mu opioid receptor (MOR) by using pharmacological antagonists and mice genetically deficient in MOR. Beginning with a paper published in 2005, evidence was presented that morphine is immune-stimulating via binding to MD2, a molecule associated with Toll-like Receptor 4 (TLR4), the receptor for bacterial lipopolysaccharide (LPS). This concept was pursued to implicate inflammation as a mechanism for the psychoactive effects of the opioid. This review considers the validity of this hypothesis and concludes that it is hard to sustain. The experiments demonstrating immunosuppression were carried out in vivo in rodent strains with normal levels of TLR4, or involved use of cells taken from animals that were wild-type for expression of TLR4. Since engagement of TLR4 is universally accepted to result in immune activation by up-regulation of NF-κB, if morphine were binding to TLR4, it would be predicted that opioids would have been found to be pro-inflammatory, which they were not. Further, morphine is immunosuppressive in mice with a defective TLR4 receptor. Morphine and morphine withdrawal have been shown to permit leakage of Gram-negative bacteria and LPS from the intestinal lumen. LPS is the major ligand for TLR4. It is proposed that an occult variable in experiments where morphine is being proposed to activate TLR4 is actually underlying sepsis induced by the opioid.

Increased pain sensitivity and decreased opioid analgesia in T-cell-deficient mice and implications for sex differences

The processing of pain in the central nervous system is now known to have an important immune component, including T cells of the adaptive immune system. T cells have been shown to release endogenous opioids, and although it is well known that opioids have effects on T-cell populations, very little attention has been given to the converse: how T cells may affect opioid regulation. We find here that, in addition to displaying significantly increased baseline pain sensitivity across various pain modalities, T-cell-deficient mice (CD-1 nude, Rag1 null mutant, and Cd4 null mutant) exhibit pronounced deficiencies in morphine inhibition of thermal or inflammatory pain. Nude mice are also deficient in endogenous opioid-mediated analgesia, exhibiting no stress-induced analgesia from restraint. The relevant T-cell subpopulation seems to be CD4 T cells because adoptive transfer of them but not CD8 cells into nude mice rescues both the pain and morphine analgesia phenotypes. As previously reported, we also observe a sex difference in CD-1 mice, with females requiring 2- to 3-fold more morphine than males to produce equal analgesia. Nude mice display no sex differences in morphine analgesia, and the sex difference is restored in nude mice of either sex receiving CD4 T cells from CD-1 donor male or female mice. These results suggest that CD4 T cells play an as yet unappreciated role in opioid analgesia and may be a driver of sex differences therein.

Members of the same pharmacological family are not alike: Different opioids, different consequences, hope for the opioid crisis?

Pain management is the specialized medical practice of modulating pain perception and thus easing the suffering and improving the life quality of individuals suffering from painful conditions. Since this requires the modulation of the activity of endogenous systems involved in pain perception, and given the large role that the opioidergic system plays in pain perception, opioids are currently the most effective pain treatment available and are likely to remain relevant for the foreseeable future. This contributes to the rise in opioid use, misuse, and overdose death, which is currently characterized by public health officials in the United States as an epidemic. Historically, the majority of preclinical rodent studies were focused on morphine. This has resulted in our understanding of opioids in general being highly biased by our knowledge of morphine specifically. However, recent in vitro studies suggest that direct extrapolation of research findings from morphine to other opioids is likely to be flawed. Notably, these studies suggest that different opioid analgesics (opioid agonists) engage different downstream signaling effects within the cell, despite binding to and activating the same receptors. This recognition implies that, in contrast to the historical status quo, different opioids cannot be made equivalent by merely dose adjustment. Notably, even at equianalgesic doses, different opioids could result in different beneficial and risk outcomes. In order to foster further translational research regarding drug-specific differences among opioids, here we review basic research elucidating differences among opioids in pharmacokinetics, pharmacodynamics, their capacity for second messenger pathway activation, and their interactions with the immune system and the dopamine D2 receptors.

Opioids in the immune system: from experimental studies to clinical practice

INTRODUCTION

Opioids interact with both innate and adaptive immune systems and have direct effects on opioid receptors located on immune cells. Research on this topic has provided evidence of the opioid influence on the immune response associated with surgical stress. The immunological effects of opioids are currently being investigated, particularly whether they influence the outcome of surgery or the underlying disease regarding important aspects like infection or cancer progression. This review addresses background research related to the influence of the opioid receptor on the immune system, the immunosuppressive effect associated with major opioids during the perioperative period, and their clinical relevance. The objective of the study was to review the effects of opioids on the immune system.

Characterization of post-surgical critical patients with infections associated with healthcare after prolonged perfusion of remifentanil

INTRODUCTION

Healthcare associated infections (HAI) are the most frequent complication of hospitalized patients. The aim of this study was to describe the clinical and epidemiological characteristics of critically ill post-surgical patients with a diagnosis of healthcare associated infections, after a pattern of sedoanalgesia of at least 4 days.

METHODS

All patients over 18 years of age with a unit admission of more than 4 days were consecutively selected. The study population was the one affected by surgical pathology where sedation was based as analgesic the opioid remifentanil for at least 96 hours in continuous perfusion. Patients who died during admission to the unit and those with combined analgesia (peripheral or neuroaxial blocks) were excluded. Data analysis was performed using the statistical package Stata version 7.0.

RESULTS

The patients admitted to the Post-Surgical Critical Care Unit (PCU) during study were 1789 and the population eligible was comprised of 102 patients. 56.86% of patients suffered IACS. The most frequent IACS was pneumonia associated with mechanical ventilation (30.96 per 1000 days of mechanical ventilation), Pseudomonas aeruginosa being the most frequently isolated germ. The germs with the greatest involvement in multiple drug resistance (MDROs) were enterobacteria, mainly Klebsiella pneumoniae resistant to extended-spectrum beta-lactamases (ESBL).

CONCLUSIONS

Pneumonia associated with mechanical ventilation is the most prevalent HAI and Pseudomonas aeruginosa is the main etiological agent. The groups of antibiotics most frequently used were cephalosporin and aminoglycosides. It is necessary to implement the prevention strategies of the different HAI, since most of them are avoidable.

Tianeptine, an atypical pharmacological approach to depression

The introduction of the first antidepressants in the 50s of the 20th century radically changed the treatment of depression, while providing information on pathophysiological aspects of this disease. New antidepressants drugs (agomelatine, tianeptine, vortioxetine) are providing data that give rise to pathophysiological hypotheses of depression that differ from the classic monoaminergic theory. In this sense, tianeptina, an atypical drug by its mechanism of differential action, contributes to clarify that in depression there is more than monoamines. Thus, tianeptine does not modify the rate of extracellular serotonin, so it does not increase or decrease the reuptake of serotonin. Chronic administration of tianeptine does not alter the density or affinity of more than a hundred classical receptors related to depression. Recently, a weak action of tianeptine on Mu opioid receptors has been described that could explain the release of dopamine in the limbic system and its participation in the modulation of glutamatergic mechanisms. These mechanisms support the hypothesis of the possible mechanism of action of this antidepressant. Tianeptine is an antidepressant, with anxiolytic properties, that can improve somatic symptoms. Tianeptine as a glutamatergic modulator, among other mechanisms, allows us to approach depression from a different point of view than other antidepressants.

Involvement of central opioid receptors in protective effects of methadone on experimental colitis in rats

PURPOSE

There are several lines of evidence on the protective roles of opioids in gastrointestinal inflammatory conditions. This study aims to distinguish the central and peripheral roles of methadone, a non-selective opioid receptor agonist, in an acute model of ulcerative colitis in male rats.

METHODS

Ulcerative colitis was induced by intrarectal administration of acetic acid 4%. Methadone was injected subcutaneously (s.c.), 5 and 10 mg/kg, and intracerebroventricular (i.c.v.), 50 and 300 ng/rat. Opioid antagonists were employed. Methylnaltrexone (MNTX; 5 mg/kg, i.p.), a peripherally acting opioid receptor antagonist, and naltrexone (NTX; 5 mg/kg, i.p. and 10 ng/rat, i.c.v.), a peripherally and centrally acting opioid receptor antagonist were injected before methadone (10 mg/kg, s.c. and or 300 ng/rat, i.c.v.) administration. NTX (5 mg/kg, i.p. and 10 ng/rat, i.c.v.) were administered 30 min prior to administration of methadone (10 mg/kg, s.c. and 300 ng/rat, i.c.v.), respectively. MNTX (5 mg/kg, i.p.) was injected 30 min prior to methadone (10 mg/kg, s.c.). Seventy-two hours following colitis induction, macroscopic and microscopic mucosal lesions, and the colonic levels of tumor necrosis factor-alpha (TNF-α) and interleukin-1β (IL-1β) were determined.

RESULTS

Methadone (300 ng/rat, i.c.v.) and Methadone (5 and 10 mg/kg, s.c.) improved the macroscopic and microscopic scores through opioid receptors. Also, a significant reduction in TNF-α and IL-1β was observed. Peripherally and centrally injected NTX significantly reversed methadone 10 mg/kg s.c. anti-inflammatory effects while MNTX could not completely reverse this effect. Moreover, centrally administered methadone (300 ng/rat) showed the anti-inflammatory effect which was reversed by central administration of NTX (10 ng/rat).

CONCLUSIONS

The opioid receptors mainly the central opioid receptors may mediate the protective actions of methadone on the experimental model of inflammatory bowel disease in rat.

Perioperative Immunosuppression and Risk of Cancer Progression: The Impact of Opioids on Pain Management

Opioids comprise an important group of drugs used in cancer pain pharmacotherapy. In recent years, more and more studies have emerged indicating the potentially immunosuppressive effects of opioid analgesics and their serious consequences, including the risk of cancer progression. The identification of these risks has prompted a search for other effective, and most importantly, safer methods of perioperative analgesic management. Regional analgesia techniques, which allow for a significant reduction in opioid dosing and thus diminish the risk of immunosuppression associated with these drugs, seem to offer substantial hope in this respect. A number of studies available in the literature assess the effects of regional analgesia techniques on cancer progression; however, it is often difficult to interpret their results owing to several perioperative factors (such as surgical trauma, inadequate pain and stress relief, and hypothermia) which are also attributed immunosuppressive effects and tend to be implicated in increased risk of cancer progression. Further research is needed to verify the available data on both the potential adverse effects of opioids and the possible protective effects of regional analgesia techniques on cancer patients.

Immunomodulatory Effects of Fentanyl or Dexmedetomidine Hydrochloride Infusion After Allogeneic Heart Transplantation in Mice

BACKGROUND AND OBJECTIVES

Postoperatively, transplant recipients receive immunosuppressants, as well as sedatives and analgesics. The immunomodulatory effects of these other agents during the induction period following transplantation remain unclear. We aimed to determine whether the agents dexmedetomidine hydrochloride (Dex) and fentanyl (Fen) have immunomodulatory effects during the induction period following heart transplantation (HTx).

METHODS

Fifty mice were used for antinociception tests after administration of Dex and Fen, and T cells from 3 naive animals were used for in vitro lymphocyte transformation test (study 1). Fifty-four B6 mice received HTx from BALB/c mice and were treated with Dex, Fen, or neither (study 2). Thirty-six recipients were used for graft survival data and were humanely killed at the time of cessation of heart graft contraction. The remaining 18 were humanely killed at either postoperative day (POD) 4 or 6 for histologic examination of graft survival, as well as in vitro analysis.

RESULTS

Based on the results of study 1, daily intraperitoneal administration of Dex at 30 μg/kg or Fen at 0.25 mg/kg was determined to be the optimal dose to induce analgesia without oversedation following HTx. Graft survivals in both Dex- or Fen-treated animals were statistically prolonged compared with control (P < 0.01). Graft survival of Fen-treated recipients was increased up to 15 days, and graft survival of Dex-treated animals was also increased up to 10 days, whereas control mice rejected heart grafts by POD 7. Mixed lymphocyte reaction responses on POD 4 showed statistically lower responses in Dex-treated recipients and Fen-treated recipients when compared with controls (P < 0.01). Cytokine profiles of splenocytes showed markedly fewer interferon γ-positive splenocytes in Fen-treated recipients on POD 4.

CONCLUSIONS

These data suggest that both Dex and Fen have immunomodulatory properties in the induction period following transplantation.

Opioids and immunosupression in oncological postoperative patients

INTRODUCTION

Recent animal studies demonstrated immunosuppressive effects of opioid withdrawal resulting in a higher risk of infection. The aim of this study was to determine the impact of remifentanil discontinuation on Post-Anesthesia Care Unit (PACU)-acquired infection after a schedule of sedoanalgesia of at least 6 days.

METHOD

All patients over 18 years of age with a unit admission of more than 4 days were consecutively selected. The study population was the one affected by surgical pathology of any origin where sedation was based on any hypnotic and the opioid remifentanil was used as analgesic for at least 96 hours in continuous perfusion. Patients who died during admission to the unit and those with combined analgesia (peripheral or neuroaxial blocks) were excluded. Bivariate analysis was performed to determine risk factors for infection acquired in the unit. A comparative study between periods of 6 days before and after the cessation of remifentanil was performed. Paired samples test and McNemar test was used for quantitative and categorical variables, respectively.

RESULTS

There were 1,789 patients admitted to the PACU during the study and the population eligible was constituted for 102 patients. The incidence rate of PACU-acquired infection was 38 per 1,000 PACU days. Ventilator-associated pneumonia was the most frequently diagnosed PACU-acquired infection. Pseudomona aeruginosa was the most frequently isolated microorganism. Hospital mortality was 36.27%. No statistically significant differences were seen in the incidence of HAI in cancer patients in relation to discontinuation of remifentanil (p=0.068).

CONCLUSION

The baseline state of immunosuppression of cancer patients does not imply a higher incidence of HAI in relation to the interruption of remifentanil. It would be of interest to carry out a multicenter PACU study that included immunological patterns.

Does Opioid Use Cause Angiogenesis and Metastasis?

Objective

To provide a comprehensive overview of the potential for morphine to lead to angiogenesis and metastasis.

Background

Morphine is often the treatment of choice for severe cancer-related pain. Small studies have been emerging that indicate that opioids may influence angiogenesis and metastasis, but this has not yet been comprehensively synthesized.

Purpose

To highlight morphine's relationship with angiogenesis and metastasis in in vitro models.

Method

A review of the literature was conducted using PubMed (1966 to 2015) and Cochrane Library (1987 to 2015) electronic databases. The search, as well as consultation with experts, yielded 84 articles for initial review, 12 of which met inclusion for review. Possible theories of the underlying etiology of the metastasis and angiogenesis were recorded.

Results

All studies were assessed using the PRISMA checklist.

Conclusion

This systematic review demonstrates that morphine has a potential causal relationship with angiogenesis and metastasis. This is likely due to multiple etiologies, including immunosuppressive, pro-inflammatory, and pro-angiogenetic.

Effects of voluntary exercise on the viability, proliferation and BDNF levels of bone marrow stromal cells in rat pups born from morphine- dependent mothers during pregnancy

This study was designed to investigate whether free access to a running wheel during pregnancy in morphine-dependent mothers would influence the viability, proliferation and BDNF levels of bone marrow stromal cells in rat pups. Pregnant rats were made dependent by chronic administration of morphine in drinking water simultaneously with free access to a running wheel. Male pups are weaned at 21days of birth and their bones marrows were aspirated from the femurs and tibias and also the bone marrow stromal cells (BMSCs) cultured. MTT assay was used to determine cell viability and proliferation rate. The level of BDNF was measured in the supernant of BMSCs culture by ELISA. The sedentary morphine-dependent mothers' pups showed a significant increase in the percentage cell viability and proliferation rate and also a significant decrease in the BDNF protein levels in BMSCs. The rat pups borne from exercising the control and morphine-dependent mothers exhibited an increase in the percentage viability, proliferation rate and BDNF levels of the BMSCs. This study showed that maternal exercise during pregnancy in morphine-dependent and non-dependent mothers, with increasing of BDNF levels increased the proliferation and viability of BMSCs in the rat pups. Also, chronic administration of morphine during pregnancy was able to increase the proliferation and viability of BMSCs in the rat pups.

Antidepressant therapies inhibit inflammation and microglial M1-polarization

Macrophages and their counterparts in the central nervous system, the microglia, detect and subsequently clear microbial pathogens and injured tissue. These phagocytic cells alter and adapt their phenotype depending on their prime activity, i.e., whether they participate in acute defence against pathogenic organisms ('M1'-phenotype) or in clearing damaged tissues and performing repair activities ('M2'-phenotype). Stimulation of pattern recognition receptors by viruses (vaccines), bacterial membrane components (e.g., LPS), alcohol, or long-chain saturated fatty acids promotes M1-polarization. Vaccine or LPS administration to healthy human subjects can result in sickness symptoms and low mood. Alcohol abuse and abdominal obesity are recognized as risk factors for depression. In the M1-polarized form, microglia and macrophages generate reactive oxygen and nitrogen radicals to eradicate microbial pathogens. Inadvertently, also tetrahydrobiopterin (BH4) may become oxidized. This is an irreversible reaction that generates neopterin, a recognized biomarker for depression. BH4 is a critical cofactor for the synthesis of dopamine, noradrenaline, and serotonin, and its loss could explain some of the symptoms of depression. Based on these aspects, the suppression of M1-polarization would limit the inadvertent catabolism of BH4. In the current review, we evaluate the evidence that antidepressant treatments (monoamine reuptake inhibitors, PDE4 inhibitors, lithium, valproate, agomelatine, tianeptine, electroconvulsive shock, and vagus nerve stimulation) inhibit LPS-induced microglia/macrophage M1-polarization. Consequently, we propose that supplementation with BH4 could limit the reduction in central monoamine synthesis and might represent an effective treatment for depressed mood.

Therapeutical Neurotargeting via Magnetic Nanocarrier: Implications to Opiate-Induced Neuropathogenesis and NeuroAIDS

Magnetite (Fe3O4) is the most commonly and extensively explored magnetic nanoparticles (MNPs) for drug-targeting and imaging in the field of biomedicine. Nevertheless, its potential application as safe and effective drug-carrier for CNS (Central Nervous System) anomalies is very limited. Previous studies have shown an entangled epidemic of opioid use and HIV infection and increased neuropathogenesis. Opiate such as morphine, heroine, etc. are used frequently as recreational drugs. Existing treatments to alleviate the action of opioid are less effective at CNS level due to impermeability of therapeutic molecules across brain barriers. Thus, development of an advanced nanomedicine based approach may pave the way for better treatment strategies. We herein report magnetic nanoformulation of a highly selective and potent morphine antagonist, CTOP (D-Pen-Cys-Tyr-DTrp-Orn-Thr-Pen-Thr-NH2), which is impenetrable to the brain. MNPs, synthesized in size range from 25 to 40 nm, were characterized by Transmission electron microscopy and assembly of MNPs-CTOP nanoformulations were confirmed by FTIR spectroscopy and fluorescent detection. Flow-cytometry analysis showed that biological efficacy of this nanoformulation in prevention of morphine induced apoptosis in peripheral blood mononuclear cells remains equivalent to that of free CTOP. Similarly, confocal microscopy reveals comparable efficacy of free and MNPs bound CTOP in protecting modulation of neuronal dendrite and spine morphology during morphine exposure and morphine-treated HIV infection. Further, typical transmigration assay showed increased translocation of MNPs across in vitro blood-brain barrier upon exposure of external magnetic force where barrier integrity remains unaltered. Thus, the developed nanoformulation could be effective in targeting brain by application of external magnetic force to treat morphine addiction in HIV patients.

The effects of cocaine on HIV transcription

Illicit drug users are a high-risk population for infection with the human immunodeficiency virus (HIV). A strong correlation exists between prohibited drug use and an increased rate of HIV transmission. Cocaine stands out as one of the most frequently abused illicit drugs, and its use is correlated with HIV infection and disease progression. The central nervous system (CNS) is a common target for both drugs of abuse and HIV, and cocaine intake further accelerates neuronal injury in HIV patients. Although the high incidence of HIV infection in illicit drug abusers is primarily due to high-risk activities such as needle sharing and unprotected sex, several studies have demonstrated that cocaine enhances the rate of HIV gene expression and replication by activating various signal transduction pathways and downstream transcription factors. In order to generate mature HIV genomic transcript, HIV gene expression has to pass through both the initiation and elongation phases of transcription, which requires discrete transcription factors. In this review, we will provide a detailed analysis of the molecular mechanisms that regulate HIV transcription and discuss how cocaine modulates those mechanisms to upregulate HIV transcription and eventually HIV replication.

Effect of sevoflurane on human hepatocellular carcinoma HepG2 cells under conditions of high glucose and insulin

Diabetes mellitus is associated with morbidity and progression of some cancers, such as hepatocellular carcinoma. It has been reported that sevoflurane, a volatile anesthetic agent commonly used in cancer surgery, can lead to lower overall survival rates than those observed when propofol is used to treat cancer patients, and sevoflurane increases cancer cell proliferation in in vitro studies. It has been also reported that glucose levels in rats anesthetized with sevoflurane were higher than those in rats anesthetized with propofol. We investigated the effect of sevoflurane, under conditions of high glucose and insulin, on cell proliferation in the human hepatocellular carcinoma cell line, HepG2. First, we exposed HepG2 cells to sevoflurane at 1 or 2 % concentration for 6 h in various glucose concentrations and then evaluated cell proliferation using the MTT assay. Subsequently, to mimic diabetic conditions observed during surgery, HepG2 cells were exposed to sevoflurane at 1 or 2 % concentration in high glucose concentrations at various concentrations of insulin for 6 h. One-percent sevoflurane exposure enhanced cell proliferation under conditions of high glucose, treated with 0.05 mg/l insulin. Our study implies that sevoflurane may affect cell proliferation in human hepatocellular carcinoma cells in a physiological situation mimicking that of diabetes.

Activation of μ opioid receptors modulates inflammation in acute experimental colitis

BACKGROUND

μ opioid receptors (μORs) are expressed by neurons and inflammatory cells, and mediate immune response. We tested whether activation of peripheral μORs ameliorates the acute and delayed phase of colitis.

METHODS

C57BL/6J mice were treated with 3% dextran sodium sulfate (DSS) in water, 5 days with or without the peripherally acting μOR agonist, [D-Ala2, N-Me-Phe4, Gly5-ol]-Enkephalin (DAMGO) or with DAMGO+μOR antagonist at day 2-5, then euthanized. Other mice received DSS followed by water for 4 weeks, or DSS with DAMGO starting at day 2 of DSS for 2 or 3 weeks followed by water, then euthanized at 4 weeks. Disease activity index (DAI), histological damage, and myeloperoxidase assay (MPO), as index of neutrophil infiltration, were evaluated. Cytokines and μOR mRNAs were measured with RT-PCR, and nuclear factor-kB (NF-kB), the antiapoptotic factor Bcl-xL, and caspase 3 and 7 with Western blot.

KEY RESULTS

DSS induced acute colitis with elevated DAI, tissue damage, apoptosis and increased MPO, cytokines, μOR mRNA, and NF-kB. DAMGO significantly reduced DAI, inflammatory indexes, cytokines, caspases, and NF-kB, and upregulated Bcl-xL, effects prevented by μOR antagonist. In DSS mice plus 4 weeks of water, DAI, NF-kB, and μOR were normal, whereas MPO, histological damage, and cytokines were still elevated; DAMGO did not reduce inflammation, and did not upregulate Bcl-xL.

CONCLUSIONS & INFERENCES

μOR activation ameliorated the acute but not the delayed phase of DSS colitis by reducing cytokines, likely through activation of the antiapoptotic factor, Bcl-xL, and suppression of NF-kB, a potentiator of inflammation.

Adenosine deaminase activity modulation by some street drug: molecular docking simulation and experimental investigation

BACKGROUND

Adenosine deaminase (ADA) is an enzyme that plays important roles in proliferation, maturation, function and development of the immune system. ADA activity may be altered by variety of substances including synthetic or natural products. Morphine, cocaine and their analogs exert immune suppressive activities by decreasing immune system function. The purpose of this study is to confirm that this possible effect may be modulated by interaction of these substances with ADA activity by experimental and computational method.

METHODS

The structural changes in ADA have been studied in presence of cocaine, ethylmorphine, homatropine, morphine and thebaine by determination of ADA hydrolytic activity, circular dichroism and fluorescence spectroscopy in different concentrations. Docking study was performed to evaluate interaction method of test compound with ADA active site using AutoDock4 software.

RESULTS

According to in-vitro studies all compounds inhibited ADA with different potencies, however thebaine activated it at concentration below 50 μM, ethylmorphine inhibited ADA at 35 μM. Moreover, fluorescence spectra patterns were differed from compounds based on structural resemblance which were very considerable for cocaine and homatropine.

CONCLUSION

The results of this study confirms that opioids and some other stimulant drugs such as cocaine can alter immune function in illegal drug abusers. These findings may lead other investigators to develop a new class of ADA activators or inhibitors in the near future.

Effects of opioids on phagocytic function, oxidative burst capacity, cytokine production and apoptosis in canine leukocytes

Opioids alter immune and apoptotic pathways in several species. They are commonly used in companion animals affected with infectious and/or inflammatory disease, but the immunomodulatory and apoptotic effects of these drugs in dogs are relatively unknown. The aim of the present study was to evaluate the effects of morphine, buprenorphine and fentanyl on canine phagocyte function, oxidative burst capacity, leukocyte cytokine production, and lymphocyte apoptosis. Blood from six healthy adult dogs was incubated in the presence or absence of morphine (200 ng/mL), buprenorphine (10 ng/mL) or fentanyl (10 ng/mL) for 3 h (phagocytic function; cytokine production) or 8 h (apoptosis). Neutrophil phagocytosis of opsonized Escherichia coli, respiratory burst capacity after stimulation with opsonized E. coli or phorbol 12-myristate 13-acetate (PMA), and Annexin V-FITC staining of apoptotic lymphocytes were evaluated using flow cytometry. Leukocyte production of tumor necrosis factor (TNF)-α, interleukin (IL)-6 and IL-10 was assessed after incubation with lipopolysaccharide (LPS), lipoteichoic acid (LTA) or peptidoglycan. Morphine promoted a more intense respiratory burst. Morphine, buprenorphine and fentanyl all promoted LPS- or LTA-induced TNF-α and IL-10 production. However, the opioids tested did not alter TNF-α:IL-10 ratios. Morphine, buprenorphine and fentanyl all inhibited neutrophil apoptosis, an effect that was not concentration dependent in nature. These data indicate that opioids alter immune and apoptotic pathways in dogs. The possible effects of opioids on immune and cellular responses should be considered when designing studies and interpreting outcomes of studies involving administration of opioids in dogs.

Opioid effect on lungs

Opioids are widely used for their analgesic properties for the management of acute and chronic pain related to a variety of illnesses. Opioid usage is associated with adverse effects on respiration which are often attributed to depression of the central nervous system. Recent data indicate that opioid use has increased over the last two decades. There is also increasing evidence that opioids have a variety of effects on the lungs besides suppression of respiration. Opioids can affect immune cells function, increase histamine release causing bronchospasm, vaso-constriction and hypersensitivity reactions. Together, these actions have a variety of effects on lung function. Here, we provide a comprehensive review of the effects of opioids on the lungs including the respiratory centre, immune function, airways and pulmonary vasculature.

Effects of Tai Chi on the protracted abstinence syndrome: a time trial analysis

While exercise has been shown to reduce the negative effects of substance withdrawal symptoms, no research has investigated if Tai Chi, a traditional Chinese exercise, has similar effects. Here, we observed the physiological effects of Tai Chi on protracted abstinence syndrome (PAS) in female heroin addicts by comprehensively inspecting their immune system function, complete blood count, hepatic function and renal function. To determine the psychological effects, we used the Hamilton Rating Scale for Depression (HRSD) and the rating scale of heroin withdrawal symptoms. We recruited 70 heroin-addicted young women beginning to undergo withdrawal and randomly assigned them into two groups: one group received one-hour Tai Chi exercise every two days (Tai Chi group, n = 36) and the other group did not (control group, n = 34). Thirty-three patients finished this six-month trial. Numerous significant physiological differences were observed between all heroin-addicted subjects (n = 70) and age-matched healthy individuals (n = 18), suggesting a deleterious effect of drug addiction. There were improvements for certain physical parameters between the Tai Chi group (n = 17) and the control group (n = 16), although the differences were not statistically significant. We observed a small significant difference in psychological effects near the 60-day mark between the two groups. Taken together, our results suggest that Tai Chi might have a positive effect on PAS, which future studies can confirm by using an expanded sample size, longer trial time, and more sensitive and specific indicators of psychological and physiological health.

Substance use disorders: psychoneuroimmunological mechanisms and new targets for therapy

An estimated 76.4 million people worldwide meet criteria for alcohol use disorders, and 15.3 million meet criteria for drug use disorders. Given the high rates of addiction and the associated health, economic, and social costs, it is essential to develop a thorough understanding of the impact of substance abuse on mental and physical health outcomes and to identify new treatment approaches for substance use disorders (SUDs). Psychoneuroimmunology is a rapidly expanding, multidisciplinary area of research that may be of particular importance to addiction medicine, as its focus is on the dynamic and complex interactions among behavioral factors, the central nervous system, and the endocrine and immune systems (Ader, 2001). This review, therefore, focuses on: 1) the psychoneuroimmunologic effects of SUDs by substance type and use pattern, and 2) the current and future treatment strategies, including barriers that can impede successful recovery outcomes. Evidence-based psychosocial and pharmacotherapeutic treatments are reviewed. Psychological factors and central nervous system correlates that impact treatment adherence and response are discussed. Several novel therapeutic approaches that are currently under investigation are introduced; translational data from animal and human studies is presented, highlighting immunotherapy as a promising new direction for addiction medicine.

Comparative effects of flurbiprofen and fentanyl on natural killer cell cytotoxicity, lymphocyte subsets and cytokine concentrations in post-surgical intensive care unit patients: prospective, randomized study

PURPOSE

The purpose of this study was to compare the effect of the long-term administration of flurbiprofen and fentanyl in the intensive care unit on natural killer cell cytotoxicity (NKCC), lymphocyte subsets and cytokine levels.

METHODS

In this prospective study, patients scheduled for at least 48 h sedation after neck surgery were randomly assigned to two groups called group N and group F. Group N patients were sedated with propofol and flurbiprofen after surgery (n = 12), while group F patients were sedated with propofol and fentanyl (n = 13). The NKCC, lymphocyte subsets, and plasma levels of tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-10 were measured before and at the end of surgery, on postoperative day (POD) 1 and POD2.

RESULTS

The NKCC was significantly higher on POD1 in group N than in group F (14.5 ± 11.2 versus 6.3 ± 4.1%, p < 0.05), the difference between the groups disappearing on POD2. Lymphocyte subsets and plasma levels of cytokines were not significantly different between the two groups during the study period.

CONCLUSIONS

Transient suppressive effects on NKCC were observed in the fentanyl group as compared to the flurbiprofen group. This suggests that when choosing postoperative analgesics, physicians should bear in mind the potential immunosuppressive effects of these agents in patients requiring prolonged sedation in the intensive care unit.

Hematological changes in opium addicted diabetic rats

Background

Chronic opioid treatment in animal models has shown to alter hematological parameters.

Objectives

The aim of this study was to evaluate the biological effects of opium on the number of peripheral blood cells and red blood cells (RBCs) indices in diabetic rats.

Materials and Methods

Peripheral blood samples were collected from diabetic, opium-addicted, diabetic opium-addicted and normal male and female rats and hematological parameters were measured.

Results

The mean number of white blood cells (WBCs) was significantly higher in diabetic opium-addict females compared to diabetic non-addict female group. In both male and female, the mean number of neutrophils was significantly higher and the mean number of lymphocytes was lower in diabetic opium-addicted rats than those observed in diabetic non-addicted group. In diabetic opium-addicted male group the mean counts of RBC significantly increased as compared with diabetic male group. However, in diabetic addicted female, the mean number of RBCs was significantly lower than diabetic non-addicted female group. In both males and females, the mean number of platelets was significantly lower in diabetic addict rats compared to diabetic non-addict group.

Conclusions

Generally, the results indicated that opium addiction has different effects on male and female rats according to the number of WBC, RBC and RBC indices. It could also be concluded that in the opium-addicts the risk of infection is enhanced due to the weakness of immune system as a result of the imbalance effect of opium on the immune cells.

Impaired toll-like receptor 3-mediated immune responses from macrophages of patients chronically infected with hepatitis C virus

Hepatitis C virus (HCV) is the most common chronic blood-borne infection in the United States, with the majority of patients becoming chronically infected and a subset (20%) progressing to cirrhosis and hepatocellular carcinoma. Individual variations in immune responses may help define successful resistance to infection with HCV. We have compared the immune response in primary macrophages from patients who have spontaneously cleared HCV (viral load negative [VL-], n = 37) to that of primary macrophages from HCV genotype 1 chronically infected (VL+) subjects (n = 32) and found that macrophages from VL- subjects have an elevated baseline expression of Toll-like receptor 3 (TLR3). Macrophages from HCV patients were stimulated ex vivo through the TLR3 pathway and assessed using gene expression arrays and pathway analysis. We found elevated TLR3 response genes and pathway activity from VL- subjects. Furthermore, macrophages from VL- subjects showed higher production of beta interferon (IFN-β) and related IFN response genes by quantitative PCR (Q-PCR) and increased phosphorylation of STAT-1 by immunoblotting. Analysis of polymorphisms in TLR3 revealed a significant association of intronic TLR3 polymorphism (rs13126816) with the clearance of HCV and the expression of TLR3. Of note, peripheral blood mononuclear cells (PBMCs) from the same donors showed opposite changes in gene expression, suggesting ongoing inflammatory responses in PBMCs from VL+ HCV patients. Our results suggest that an elevated innate immune response enhances HCV clearance mechanisms and may offer a potential therapeutic approach to increase viral clearance.

Cocaine and HIV-1 interplay in CNS: cellular and molecular mechanisms

Although antiretrovirals are the mainstay of therapy against HIV infection, neurological complications associated with the virus continue to hamper quality of life of the infected individuals. Drugs of abuse in the infected individuals further fuel the epidemic. Epidemiological studies have demonstrated that abuse of cocaine resulted in acceleration of HIV infection and the progression of NeuroAIDS. Cocaine has not only been shown to play a crucial role in promoting virus replication, but also has diverse but often deleterious effects on various cell types of the CNS. In the neuronal system, cocaine exposure results in neuronal toxicity and also potentiates gp120-induced neurotoxicity. In the astroglia and microglia, cocaine exposure leads to up-regulation of pro-inflammatory mediators such as cytokines and chemokines. These in turn, can lead to neuroinflammation and transmission of toxic responses to the neurons. Additionally, cocaine exposure can also lead to leakiness of the blood-brain barrier that manifests as enhanced transmigraiton of leukocytes/monocytes into the CNS. Both in vitro and in vivo studies have provided valuable tools in exploring the role of cocaine in mediating HIV-associated neuropathogenesis. This review summarizes previous studies on the mechanism(s) underlying the interplay of cocaine and HIV as it relates to the CNS.

Regulation of mu opioid receptor expression in developing T cells

We have previously reported that functionally active μ-opioid receptors (MOR) are constitutively expressed at relatively low levels by developing T cells in the thymus. However, very little is known about the regulation of MOR expression by immature T cells. In this report, we first attempted to determine the effect of T cell receptor-induced T cell activation on the expression of MOR. We activated T cells with either the combination of anti-CD3 and CD28, or with superantigen, and observed a substantial increase in MOR transcript expression. We also chose to examine the effect of cytokine-mediated T cell activation on the expression of this opioid receptor. We selected certain cytokines that play a role in T cell development and are known to be present at functional levels in the thymus gland. Our results show that interferon γ (IFNγ), IL-1β, and IL-2, and in particular transforming growth factor-β (TGFβ), all induced significant increases in MOR transcript expression. On the other hand, both TNFα and IL-7 exhibited much weaker effects on MOR expression. These results show that MOR expression by developing T cells is strongly regulated by several cytokines involved in T cell development in the thymus gland.

Methadone diminishes neuroinflammation and disease severity in EAE through modulating T cell function

Methadone is known to exert modulatory effects on the immune system. We investigated the potential effects of methadone on infiltration of inflammatory cells into the spinal cord, as well as the proliferative and cytokine responses of T cells in MOG(35-55)-induced experimental autoimmune encephalomyelitis in mice. Methadone significantly suppressed clinical signs of the disease and level of inflammatory cytokines (p<0.05) produced by T cells. Moreover, invasion of inflammatory cells into the spinal cord was significantly decreased by methadone (p<0.05). Our data point to therapeutic effects of methadone and highlight the beneficial role of opioid receptor signaling in the context of autoimmune neuroinflammation.

[Influence of anesthesia procedure on malignant tumor outcome]

Malignant tumors are the second major cause of death in Germany. The essential therapy of operable cancer is surgical removal of primary tumors combined with adjuvant therapy. However, several consequences of surgery may promote metastasis, such as shedding of tumor cells into the circulation, decrease in tumor-induced antiangiogenesis factors, excessive release of growth factors for wound healing and suppression of immunity induced by surgical stress. In the last decade it has become clear that cell-mediated immunity controls the development of metastasis. Various perioperative factors, such as surgical stress, certain anesthetic and analgesic drugs and pain can suppress the patients' immune system perioperatively. On the other hand, by modifications of the anesthesia technique (e.g. regional anesthesia) and perioperative management to minimize immunosuppression, anesthesiologists can play a considerable role for a better outcome in patients having malignant tumors. Sufficient clinical evidence is not yet available to prove or disprove the hypothesis that anesthesia practice can improve cancer prognosis. Despite difficulties in study design, several prospective randomized trials are currently running and the results are awaited to elucidate this topic.