Long-term Low-dose Treatment Research Articles

Sodium arsenite does not affect prostate carcinogenesis in a chemically-hormonally-induced rat model

There is epidemiologic evidence to suggest that arsenic exposure is associated with risk of prostate cancer incidence and mortality. There are no studies indicating that arsenic can induce prostate cancer in animals. We evaluated whether drinking water exposure to sodium arsenite would affect prostate carcinogenesis in a rat model that depends on long-term low dose treatment with testosterone. WU rats received a sequential treatment with the antiandrogen flutamide followed by a single androgen administration to stimulate prostatic cell proliferation during which a single injection of N-methyl-N-nitrosourea was given. Two weeks later the animals received subcutaneous slow release testosterone-containing silastic tubing implants and provided with drinking water containing 5 mg/L sodium arsenite or with control drinking water for the duration of the 64 week-long experiment. Arsenite provided in drinking water did not modify the induction of prostate cancer in this rat model compared to control rats or survival. It also did not affect the growth of the animals or their drinking water intake. This animal study with drinking water exposure to 5 mg/L sodium arsenite does not support the notion that arsenic enhances prostate carcinogenesis.

High prevalence of steroid-induced glucose intolerance with normal fasting glycaemia during low-dose glucocorticoid therapy: an oral glucose tolerance test screening study.

To evaluate the prevalence and risk factors of new-onset glucose metabolism impairment using an oral glucose tolerance test (OGTT) in patients with normal fasting glycaemia on long-term glucocorticoid (GC) treatment. An OGTT was performed in 150 patients without a previous history of pre-diabetes or diabetes who were diagnosed with inflammatory rheumatic diseases and treated with GCs >3 months. All participants underwent clinical and biochemical evaluation for risk factors of diabetes: age, sex, current and cumulative dose of steroids, treatment duration, waist circumference, BMI, Homeostatic Model Assessment for Insulin Resistance, fasting insulin concentration, family history of diabetes, CRP, 28-joint DAS with CRP, type of connective tissue disease and trunk fat percentage measured by DXA. Logistic regression analysis was conducted to evaluate the association between the presence of impaired glucose tolerance (IGT) in the OGTT and analysed risk factors. A total of 102 patients (68%) had fully normal glucose tolerance. Diabetes, isolated impaired fasting glucose, isolated IGT and combined impaired fasting glucose + IGT was diagnosed in 3.3, 4.67, 19.33 and 4.67% of patients, respectively; 20% of participants had IGT or diabetes despite normal fasting glucose concentration. The median cumulative dose and current dose (5 mg) of GCs and treatment duration were similar compared with the normal glucose tolerance group. In a multivariate logistic regression model, only older age (particularly ≥50 years of age) and trunk fat percentage remained significant factors predicting IGT or diabetes in the OGTT. New-onset GC-induced glucose intolerance, even in patients on long-term low-dose treatment, is prevalent despite normal fasting glucose concentration and patients should be screened with an OGTT despite the absence of classic risk factors of diabetes.

Novelties in the treatment of pediatric immune thrombocytopenia - 2017

Immune thrombocitopenia in children is a very variable disease. International recommendations give therapeutic possibilities without strong protocols. In 2011, a therapeutic algorithm was published based on Hungarian practice. Recently, new innovative drugs have been available even in Hungary, so there is a need for modification of the therapeutic protocols. In this summary we give an overview about the current up-to-date management. In infancy and in childhood, high-dose immunglobulin treatment is recommended henceforward. In older children an alternative can be steroid therapy (pulses or long-term low-dose treatment). In resistant cases, a new thrombopoetin receptor stimulant, eltrombopag can be administered. This drug is registered in Hungary, and can very effectively influence the prognosis. Splenectomy is very rare nowadays in children. Immune thrombocytopenia is an unpredictable disease. Cure rate is about 70-80% of the cases, but management of the patients needs special care and specialist. Orv Hetil. 2017; 158(48): 1891-1896.

Persistent inhibition of pore-based cell migration by sub-toxic doses of miuraenamide, an actin filament stabilizer

Opposed to tubulin-binding agents, actin-binding small molecules have not yet become part of clinical tumor treatment, most likely due to the fear of general cytotoxicity. Addressing this problem, we investigated the long-term efficacy of sub-toxic doses of miuraenamide, an actin filament stabilizing natural compound, on tumor cell (SKOV3) migration. No cytotoxic effects or persistent morphological changes occurred at a concentration of miuraenamide of 20 nM. After 72 h treatment with this concentration, nuclear stiffness was increased, causing reduced migration through pores in a Boyden chamber, while cell migration and chemotaxis per se were unaltered. A concomitant time-resolved proteomic approach showed down regulation of a protein cluster after 56 h treatment. This cluster correlated best with the Wnt signaling pathway. A further analysis of the actin associated MRTF/SRF signaling showed a surprising reduction of SRF-regulated proteins. In contrast to acute effects of actin-binding compounds on actin at high concentrations, long-term low-dose treatment elicits much more subtle but still functionally relevant changes beyond simple destruction of the cytoskeleton. These range from biophysical parameters to regulation of protein expression, and may help to better understand the complex biology of actin, as well as to initiate alternative regimes for the testing of actin-targeting drugs.

The supplementary therapeutic DMARD role of low-dose glucocorticoids in rheumatoid arthritis.

The management of rheumatoid arthritis (RA) is primarily based on the use of disease-modifying antirheumatic drugs (DMARDs), mainly comprising synthetic chemical compounds (that is, methotrexate or leflunomide) and biological agents (tumor necrosis factor inhibitors or abatacept). On the other hand, glucocorticoids (GCs), used for decades in the treatment of RA, are effective in relieving signs and symptoms of the disease, but also interfere with radiographic progression, either as monotherapy or in combination with conventional synthetic DMARDs. GCs exert most of their biological effects through a genomic action, using the cytosolic GC receptor and then interacting with the target genes within target cells that can result in increased expression of regulatory - including anti-inflammatory - proteins (transactivation) or decreased production of proinflammatory proteins (transrepression). An inadequate secretion of GCs from the adrenal gland, in relation to stress and inflammation, seems to play an important role in the pathogenesis and disease progression of RA. At present there is clear evidence that GC therapy, especially long-term low-dose treatment, slows radiographic progression by at least 50% when given to patients with early RA, hence satisfying the conventional definition of a DMARD. In addition, long-term follow-up studies suggest that RA treatment strategies which include GC therapy may favorably alter the disease course even after their discontinuation. Finally, a low-dose, modified night-release formulation of prednisone, although administered in the evening (replacement therapy), has been developed to counteract the circadian (night) rise in proinflammatory cytokine levels that contributes to disease activity, and might represent the way to further optimize the DMARD activity exerted by GCs in RA.

Anti-inflammatory effects of long-term low-dose clarithromycin administration in patients with nasal polyposis

BackgroundIn the recently performed studies, various investigators have shown considerable interest in the immunomodulatory and anti-inflammatory action of the macrolide antibiotics for long-term low-dose treatment of chronic rhinosinusitis and nasal...

Long-term low-dose antibiotics in recalcitrant chronic rhinosinusitis: a retrospective analysis

In recalcitrant Chronic RhinoSinusitis (CRS) treatment with intranasal corticosteroids, short-term antibiotics and even sinus surgery is frequently insufficient. Long-term low-dose administration of antibiotics has been suggested as a treatment option in these patients. We analysed the outpatient clinic population treated with different long-term low-dose antibiotics at the AMC Amsterdam. Eligible patients, who were treated with trimethoprim-sulfamethoxazole or macrolides, were retrospectively identified from our outpatient clinic in 2009. The two main outcome measures were sinonasal complaints and nasal endoscopic findings. A 5-point grading scale was used to score the results compared with the pre-treatment situation. This was measured at several time-points during, and after the antibiotic course, and at the end of the follow-up term. Seventy-six patients were included, 53 per cent had asthma and all of them had undergone sinus surgery. Seventy-eight per cent showed improvement of the symptoms, and 84 per cent demonstrated improvement of the sinonasal mucosa at the end of the course. No significant difference was found between the trimethoprim-sulfamethoxazole and macrolide group. Long-term low-dose treatment with antibiotics seems to improve CRS symptoms and the appearance of the sinonasal mucosa on nasal endoscopy. However, at this stage, strong conclusions are immature because no placebo-group has been included. Despite increasing use of long-term low-dose treatment of recalcitrant CRS in referral centres, hard clinical evidence is lacking. More research is urgently required.

Immunomodulatory and Clinical Effects of Long-Term Low-Dose Macrolide Treatment of Chronic Rhinosinusitis with Nasal Polyposis

Immunomodulatory and Clinical Effects of Long-Term Low-Dose Macrolide Treatment of Chronic Rhinosinusitis with Nasal PolyposisImmunomodulatory treatment of chronic rhinosinusitis with nasal polyposis (CRSwNP) by macrolide antibiotics represents a challenging alternative to conventional therapy and surgery, still being at the very beginning. Immune and inflammatory processes in nasal and paranasal sinus mucosa, crucial in the etiopathogenesis of nasal polyps (NPs) are reflected in levels of various local mediators, found both in mucosa and nasal fluid. In this prospective study, we assessed the immunomodulatory and clinical effects of longterm low-dose oral macrolide treatment in the management of CRSwNP. Twenty-two (n = 22) nonasthmatic, nonallergic patients with CRSwNP were administered clarithromycin (CAM) 500 mg/day single oral dose for eight weeks. We measured the levels of proinflammatory cytokines TNF-α, TNF-β, and IL-1β, Th1 cytokines IL-2, IL-12, and IFN-γ, Th2 cytokines IL-4, IL-5, IL-6, and IL-10, and chemokine IL-8 in the nasal fluid samples, before and after treatment, using a flow cytometric method. We also scored each of the 22 patients before and after therapy according to Tsicopoulos' global nasal symptom score and Malm's endoscopic score. Following treatment, we found significantly reduced levels of IL-8 (p<0.01) and TNF-α (p<0.01) in nasal secretions. Macrolide therapy decreased the size of polyps in 45.45% of the patients. We concluded that long-term low-dose treatment with CAM was effective in the management of CRSwNP. We suggest that macrolides can be an alternative to topical and systemic corticosteroids in the management of CRSwNP.

Ageing‐related corpora veno‐occlusive dysfunction in the rat is ameliorated by pioglitazone

To determine whether ageing-related changes in the penile corpora cavernosa, namely corporal veno-occlusive dysfunction (CVOD), loss of smooth muscle cells (SMCs), and excessive collagen deposition, can be ameliorated by the peroxisome proliferator-activated receptor gamma (PPARgamma) agonist pioglitazone, in a rat model of ageing as we have shown in a rat model of type 2 diabetes. Male Fischer 344 rats (16-18 months old) were fed chow containing 0%, 0.001% or 0.02% pioglitazone for 2 or 4.5 months, using 5 month old rats as 'young' controls. Functional changes were determined by dynamic-infusion cavernosometry (DIC). Histological changes were assessed by histochemistry and immunohistochemistry followed by quantitative image analysis and/or quantitative Western blot. Reactive oxygen species were estimated in blood. Pioglitazone at both doses reduced the high DIC 'drop rate' present in the untreated aged groups to the level seen in the young rats. The papaverine response was increased to young control levels by short-term high-dose pioglitazone and the long-term low-dose treatment, but not by the short-term low-dose treatment. Pioglitazone at all doses and durations of treatment failed to reverse the decreased corporal SMC/collagen ratio and SMC content, oxidative stress, or the elevated contents of collagen, or transforming growth factor beta1, seen in the aged penis, but did reduce the collagen III/I ratio, and at a high dose increased apoptosis. Both treatments inhibited the Rho-kinase system, by increasing Src homology region 2-containing protein tyrosine phosphatase and reducing Vav. PPARgamma were detected in corporal SMCs. Pioglitazone ameliorated ageing-related CVOD, possibly by a PPARgamma-mediated inhibition of Rho-kinase and not by a protective effect on the corporal smooth muscle.

584 Long-term low dose treatment with pegylated interferon α-2b leads to a significant reduction in fibrosis in chronic hepatitis C nonresponder patients

584 Long-term low dose treatment with pegylated interferon α-2b leads to a significant reduction in fibrosis in chronic hepatitis C nonresponder patients