Platelet aggregation in portal hypertension and its modification by ultra-low doses of aspirin

Impact of Aspirin Use on Outcomes in Patients With Hepatocellular Cancer: A Nationwide Analysis

Background

Despite the use of new immunotherapies, hepatocellular carcinoma (HCC) has a poor survival rate. Through multiple molecular mechanisms, aspirin (ASA) has demonstrated a reduced incidence of HCC, however, the impact of long-term ASA use on in-hospital outcomes has not been studied.

Methods

We queried the National Inpatient Sample (NIS) database from 2016 to 2020 to identify patients with HCC. Patients were stratified into two groups, based on long-term ASA use. Information was collected regarding patient demographics, Elixhauser comorbidities, interventions, etiology, and decompensations of liver disease. Outcomes studied included sepsis, shock, acute kidney injury (AKI), intensive care unit (ICU) admission, and in-hospital mortality. The association between long-term ASA use and outcomes was studied using multivariate analysis.

Results

A total of 224,735 patients were included in the study. Of them, 18,835 (8.4%) patients were on long-term ASA. The majority of the patients with ASA use were White (61.3%), men (78.2%), and aged > 65 years old (68.8%). Patients in the ASA group had a higher incidence of non-alcoholic steatohepatitis (NASH) and decreased rates of hepatic decompensation than those not on ASA. Patients with ASA use had lower incidence of sepsis (2.76% vs. 3.54%), shock (4.86% vs. 8.23%), AKI (30.9% vs. 33.4%), ICU admission (3.88% vs. 7.4%) and in-hospital mortality (5.18% vs. 9.87%). After adjusting for confounding factors, ASA use was associated with a 30% lower risk of in-hospital mortality (adjusted odds ratio (aOR): 0.70, 95% confidence interval (CI): 0.60 - 0.82, P < 0.001). ASA users also had 21% lower odds of developing shock (aOR: 0.79, 95% CI: 0.67 - 0.94, P = 0.007) and 31% lower odds of requiring ICU admission (aOR: 0.69, 95% CI: 0.54 - 0.78, P < 0.001).

Conclusions

Our study noted that patients on long-term ASA use had better in-hospital outcomes such as mortality, shock, and ICU admissions compared to non-ASA users. These findings are of interest, and further randomized clinical trials confirming the benefits of ASA in improving outcomes in HCC patients need to be conducted.

Emerging Therapeutic Targets for Portal Hypertension

Purpose of Review

Portal hypertension is responsible of the main complications of cirrhosis, which carries a high mortality. Recent treatments have improved prognosis, but this is still far from ideal. This paper reviews new potential therapeutic targets unveiled by advances of key pathophysiologic processes.

Recent Findings

Recent research highlighted the importance of suppressing etiologic factors and a safe lifestyle and outlined new mechanisms modulating portal pressure. These include intrahepatic abnormalities linked to inflammation, fibrogenesis, vascular occlusion, parenchymal extinction, and angiogenesis; impaired regeneration; increased hepatic vascular tone due to sinusoidal endothelial dysfunction with insufficient NO availability; and paracrine liver cell crosstalk. Moreover, pathways such as the gut-liver axis modulate splanchnic vasodilatation and systemic inflammation, exacerbate liver fibrosis, and are being targeted by therapy. We have summarized studies of new agents addressing these targets.

Summary

New agents, alone or in combination, allow acting in complementary mechanisms offering a more profound effect on portal hypertension while simultaneously limiting disease progression and favoring regression of fibrosis and of cirrhosis. Major changes in treatment paradigms are anticipated.

Current and investigational drugs in early clinical development for portal hypertension

Introduction

The development of portal hypertension leads to a majority of complications associated with chronic liver disease. Therefore, adequate treatment of portal hypertension is crucial in the management of such patients. Current treatment options are limited and consist mainly of medications that decrease the hyperdynamic circulation, such as non-selective beta blockers, and treatment of hypervolemia with diuretics. Despite these options, mortality rates have not improved over the last two decades. Newer, more effective treatment options are necessary to help improve survival and quality of life in these patients.

Areas covered

Multiple preclinical models and clinical studies have demonstrated potential efficacy of a variety of new treatment modalities. We introduce treatment options including the use of vasodilation promotors, vasoconstriction inhibitors, anticoagulants, antiangiogenics, and anti-inflammatory drugs. We examine the most recent studies for treatment options within these drug classes and offer insights as to which show the most promise in this field.

Methodology

Published studies that identified novel medical treatment options of portal hypertension were searched using PubMed (https://pubmed.ncbi.nlm.nih.gov/). Clinical trials listed in Clinicaltrials.gov were also searched with a focus on more recent and ongoing studies, including those with completed recruitment. Searching with key terms including "portal hypertension" as well as individually searching specific treatment medications that were listed in other publications was carried out. Finally, current societal guidelines and recent review articles relevant to the management of portal hypertension were evaluated, and listed references of interest were included.

Conclusion

Many ongoing early phase studies demonstrate promising results and may shape the field of portal hypertension management in future. As concrete results become available, larger RCTs will be required before making definitive conclusions regarding safety and efficacy and whether or not they can be incorporated into routine clinical practice. Statins, anticoagulants, and PDE inhibitors have been among the most studied and appear to be most promising.

Replications of fundamental research models in ultra high dilutions 1994 and 2015--update on a bibliometric study

INTRODUCTION

This paper focuses exclusively on experimental models with ultra high dilutions (i.e. beyond 10(-23)) that have been submitted to replication scrutiny. It updates previous surveys, considers suggestions made by the research community and compares the state of replication in 1994 with that in 2015.

METHODS

Following literature research, biochemical, immunological, botanical, cell biological and zoological studies on ultra high dilutions (potencies) were included. Reports were grouped into initial studies, laboratory-internal, multicentre and external replications. Repetition could yield either comparable, or zero, or opposite results. The null-hypothesis was that test and control groups would not be distinguishable (zero effect).

RESULTS

A total of 126 studies were found. From these, 28 were initial studies. When all 98 replicative studies were considered, 70.4% (i.e. 69) reported a result comparable to that of the initial study, 20.4% (20) zero effect and 9.2% (9) an opposite result. Both for the studies until 1994 and the studies 1995-2015 the null-hypothesis (dominance of zero results) should be rejected. Furthermore, the odds of finding a comparable result are generally higher than of finding an opposite result. Although this is true for all three types of replication studies, the fraction of comparable studies diminishes from laboratory-internal (total 82.9%) to multicentre (total 75%) to external (total 48.3%), while the fraction of opposite results was 4.9%, 10.7% and 13.8%. Furthermore, it became obvious that the probability of an external replication producing comparable results is bigger for models that had already been further scrutinized by the initial researchers.

CONCLUSIONS

We found 28 experimental models which underwent replication. In total, 24 models were replicated with comparable results, 12 models with zero effect, and 6 models with opposite results. Five models were externally reproduced with comparable results. We encourage further replications of studies in order to learn more about the model systems used.

Beneficial effect of ultra-low-dose aspirin in platelet activity alterations and haemorrhage observed in experimental portal hypertension

Ultra-low-dose aspirin has shown a prothrombotic effect in the laser-induced thrombosis model. Several studies of our laboratory have shown a positive effect in rats with two different experimental models of portal hypertension: portal vein ligation, a model with an almost normal liver, and 30 days of bile duct ligation, a model with cirrhosis and presence of ascitis. In both models of portal hypertensive rats, bleeding time was prolonged and thrombi formation, in a laser-induced model of thrombi production, decreased. The hypotheses of the presented studies were that ultra-low-dose aspirin could decrease the bleeding complications in these models and that the mechanism for these effects could act thorough the COX pathway. In different studies, ultra-low dose of aspirin normalized the induced hemorrhage time, thrombi production, and platelet-endothelial cell interaction. The possible beneficial role of these doses of aspirin and mechanism of COX 2 inhibition are discussed.

Homeopathic Doses of Gelsemium sempervirens Improve the Behavior of Mice in Response to Novel Environments

Gelsemium sempervirens is used in homeopathy for treating patients with anxiety related symptoms, however there have been few experimental studies evaluating its pharmacological activity. We have investigated the effects of homeopathic doses of G. sempervirens on mice, using validated behavioral models. Centesimal (CH) dilutions/dynamizations of G. sempervirens, the reference drug diazepam (1 mg/kg body weight) or a placebo (solvent vehicle) were intraperitoneally delivered to groups of mice of CD1 strain during 8 days, then the effects were assessed by the Light-Dark (LD) choice test and by the Open-Field (OF) exploration test, in a fully blind manner. In the LD test, the mean time spent in the illuminated area by control and placebo-treated animals was 15.98%, for mice treated with diazepam it increased to 19.91% (P = .047), while with G. sempervirens 5 CH it was 18.11% (P = .341, non-significant). The number of transitions between the two compartments increased with diazepam from 6.19 to 9.64 (P < .001) but not with G. Sempervirens. In the OF test, G. sempervirens 5 CH significantly increased the time spent and the distance traveled in the central zone (P = .009 and P = .003, resp.), while diazepam had no effect on these OF test parameters. In a subsequent series of experiments, G. sempervirens 7 and 30 CH also significantly improved the behavioral responses of mice in the OF test (P < .01 for all tested variables). Neither dilutions of G. sempervirens affected the total distance traveled, indicating that the behavioral effect was not due to unspecific changes in locomotor activity. In conclusion, homeopathic doses of G. sempervirens influence the emotional responses of mice to novel environments, suggesting an improvement in exploratory behavior and a diminution of thigmotaxis or neophobia.

Hormesis and its relationship with homeopathy

Homeopathy is an ancient and complex therapeutic method that is rediscovering its scientific foundations. Hormesis is a frequently observed phenomenon that has been rigorously reported with precise dose-response curves. The therapeutic method based on the principle of ‘like cures like’ should not be confused with hormesis, which has several different implications from those of homeopathy. Yet, because both these approaches to nature and medicine are very broad in scope, they do end up having some points of contact. Thus, the well-established and consolidated field of hormesis can help cast light, through its ideas and research methods, on the possible mechanisms of action of remedies in ultra-low doses.

Dose-effect study of Gelsemium sempervirens in high dilutions on anxiety-related responses in mice

INTRODUCTION

This study was designed to investigate the putative anxiolytic-like activity of ultra-low doses of Gelsemium sempervirens (G. sempervirens), produced according to the homeopathic pharmacopeia.

METHODS

Five different centesimal (C) dilutions of G. sempervirens (4C, 5C, 7C, 9C and 30C), the drug buspirone (5 mg/kg) and solvent vehicle were delivered intraperitoneally to groups of ICR-CD1 mice over a period of 9 days. The behavioral effects were assessed in the open-field (OF) and light-dark (LD) tests in blind and randomized fashion.

RESULTS

Most G. sempervirens dilutions did not affect the total distance traveled in the OF (only the 5C had an almost significant stimulatory effect on this parameter), indicating that the medicine caused no sedation effects or unspecific changes in locomotor activity. In the same test, buspirone induced a slight but statistically significant decrease in locomotion. G. sempervirens showed little stimulatory activity on the time spent and distance traveled in the central zone of the OF, but this effect was not statistically significant. In the LD test, G. sempervirens increased the % time spent in the light compartment, an indicator of anxiolytic-like activity, with a statistically significant effect using the 5C, 9C and 30C dilutions. These effects were comparable to those of buspirone. The number of transitions between the compartments of the LD test markedly increased with G. sempervirens 5C, 9C and 30C dilutions.

CONCLUSION

The overall pattern of results provides evidence that G. sempervirens acts on the emotional reactivity of mice, and that its anxiolytic-like effects are apparent, with a non-linear relationship, even at high dilutions.

Assays of homeopathic remedies in rodent behavioural and psychopathological models

The first part of this paper reviews the effects of homeopathic remedies on several models of anxiety-like behaviours developed and described in rodents. The existing literature in this field comprises some fifteen exploratory studies, often published in non-indexed and non-peer-reviewed journals. Only a few results have been confirmed by multiple laboratories, and concern Ignatia, Gelsemium, Chamomilla (in homeopathic dilutions/potencies). Nevertheless, there are some interesting results pointing to the possible efficacy of other remedies, and confirming a statistically significant effect of high dilutions of neurotrophic molecules and antibodies. In the second part of this paper we report some recent results obtained in our laboratory, testing Aconitum, Nux vomica, Belladonna, Argentum nitricum, Tabacum (all 5CH potency) and Gelsemium (5, 7, 9 and 30CH potencies) on mice using ethological models of behaviour. The test was performed using coded drugs and controls in double blind (operations and calculations). After an initial screening that showed all the tested remedies (except for Belladonna) to have some effects on the behavioural parameters (light-dark test and open-field test), but with high experimental variability, we focused our study on Gelsemium, and carried out two complete series of experiments. The results showed that Gelsemium had several effects on the exploratory behaviour of mice, which in some models were highly statistically significant (p < 0.001), in all the dilutions/dynamizations used, but with complex differences according to the experimental conditions and test performed. Finally, some methodological issues of animal research in this field of homeopathy are discussed. The "Gelsemium model" - encompassing experimental studies in vitro and in vivo from different laboratories and with different methods, including significant effects of its major active principle gelsemine - may play a pivotal rule for investigations on other homeopathic remedies.

Review article: blood platelet number and function in chronic liver disease and cirrhosis

BACKGROUND

The liver plays a central role in coagulation and fibrinolysis but is also closely intertwined with the function and number of blood platelets.

AIM

To describe and integrate all literature concerning blood platelets and liver disease by performing a thorough literature research.

METHODS

A thorough literature research on 'blood platelets' and 'liver disease' was performed.

RESULTS

Thrombocytopenia is a marked feature of chronic liver disease and cirrhosis. Traditionally, this thrombocytopenia was attributed to passive platelet sequestration in the spleen. More recent insights suggest an increased platelet breakdown and to a lesser extent decreased platelet production plays a more important role. Besides the reduction in number, other studies suggest functional platelet defects. This platelet dysfunction is probably both intrinsic to the platelets and secondary to soluble plasma factors. It reflects not only a decrease in aggregability, but also an activation of the intrinsic inhibitory pathways. The net effect, finally, is a decreased platelet function in the various types of chronic liver diseases and cirrhosis. Finally, recent data suggest that platelets are not only affected by but can also contribute to the liver disease process, as for instance, in viral hepatitis and cholestatic liver disease.

CONCLUSION

Platelet research in liver disease is a growing area of investigation and could provide new pathophysiological insights.

Modifications produced by selective inhibitors of cyclooxygenase and ultra low dose aspirin on platelet activity in portal hypertension

AIM: To study the mechanism involved in the potentially beneficial effect of ultra low dose aspirin (ULDA) in prehepatic portal hypertension, rats were pretreated with selective COX 1 or 2 inhibitors (SC-560 or NS-398 respectively), and subsequently injected with ULDA or placebo.

METHODS: Portal hypertension was induced by portal vein ligation. Platelet activity was investigated with an in vivo model of laser induced thrombus production in mesenteric circulation and induced hemorrhagic time (IHT). Platelet aggregation induced by ADP and dosing of prostanoid products 6-keto-PGF_1α, TXB₂, PGE₂ and LTB₄ were also performed.

RESULTS: The portal hypertensive group receiving a placebo showed a decreased in vivo platelet activity with prolonged IHT, an effect that was normalized by ULDA. SC-560 induced a mild antithrombotic effect in the normal rats, and an unmodified effect of ULDA. NS-398 had a mild prothrombotic action in portal hypertensive rats, similar to ULDA, but inhibited a further effect when ULDA was added. An increased 6-keto-PGF_1α was observed in portal hypertensive group that was normalised after ULDA administration. TXA₂ level after ULDA, remained unchanged.

CONCLUSION: These results suggest that the effect of ULDA on platelet activity in portal hypertensive rats, could act through a COX 2 pathway more than the COX 1, predominant for aspirin at higher doses.

Modifications produced by indomethacin and L-NAME in the effect of ultralow-dose aspirin on platelet activity in portal hypertension

In our previous study, we demonstrated the effect of ultralow-dose aspirin (ULDA) on platelet activity and bleeding in rats with portal hypertension (PHT) produced by portal vein ligation (PVL). This paper reports modifications in this effect caused by blocking NO production by nitro arginine methyl ester (NAME) and cyclooxygenase (COX) activity with indomethacin. PVL rats and sham-operated controls were treated with placebo, indomethacin or NAME and 30 min thereafter with placebo or ULDA treatment. Platelet activity was studied by a model of in vivo laser-induced thrombus production in the mesenteric circulation, induced hemorrhage time (IHT) and platelet aggregation ex vivo induced by adenosine diphosphate in an aggregometer. The PVL group receiving placebo showed a decreased platelet activity with prolonged IHT, an effect that was reversed by ULDA. Indomethacin induced a decreased platelet activity in the control rats and a prolonged IHT. In PHT with ULDA, in vivo platelet activity was enhanced but the normalization of IHT observed in rats without indomethacin was blunted. The addition of NAME normalized the diminished in vivo platelet aggregation and increased the IHT observed in PVL animals. These changes decreased the effect of ULDA in both sham-operated and PVL animals. The effect of indomethacin was more clearly modified by ULDA than the effect of NAME, thus suggesting that modifications in the COX pathway might alter the effect of ULDA. The simultaneous administration of indomethacin and ULDA could inhibit its beneficial effect on bleeding in rats with PHT.

Immunology and homeopathy. 3. Experimental studies on animal models

A search of the literature and the experiments carried out by the authors of this review show that there are a number of animal models where the effect of homeopathic dilutions or the principles of homeopathic medicine have been tested. The results relate to the immunostimulation by ultralow doses of antigens, the immunological models of the ‘simile’, the regulation of acute or chronic inflammatory processes and the use of homeopathic medicines in farming. The models utilized by different research groups are extremely etherogeneous and differ as the test medicines, the dilutions and the outcomes are concerned. Some experimental lines, particularly those utilizing mice models of immunomodulation and anti-inflammatory effects of homeopathic complex formulations, give support to a real effect of homeopathic high dilutions in animals, but often these data are of preliminary nature and have not been independently replicated. The evidence emerging from animal models is supporting the traditional ‘simile’ rule, according to which ultralow doses of compounds, that in high doses are pathogenic, may have paradoxically a protective or curative effect. Despite a few encouraging observational studies, the effectiveness of the homeopathic prevention or therapy of infections in veterinary medicine is not sufficiently supported by randomized and controlled trials.