Tadalafil analgesia in experimental arthritis involves suppression of intra-articular TNF release

BACKGROUND AND PURPOSE

We investigated the effect of the phosphodiesterase-5 inhibitor, tadalafil, on the acute hypernociception in rat models of arthritis.

EXPERIMENTAL APPROACH

Rats were treated with either an intra-articular injection of zymosan (1 mg) or surgical transection of the anterior cruciate ligament (as an osteoarthritis model). Controls received saline intra-articular or sham operation respectively. Joint pain was evaluated using the articular incapacitation test measured over 6 h following zymosan or between 4 and 7 days after anterior cruciate ligament transection. Cell counts, tumour necrosis factor-α (TNF-α), interleukin-1 (IL-1), and the chemokine, cytokine-induced neutrophil chemoattractant-1 (CINC-1) were measured in joint exudates 6 h after zymosan. Groups received tadalafil (0.02-0.5 mg·kg⁻¹ per os) or saline 2 h after intra-articular zymosan. Other groups received the µ-opioid receptor antagonist naloxone or the cGMP inhibitor 1H-[1,2,4] oxadiazolo [4,3-a] quinoxalin-1-one (ODQ) before tadalafil.

KEY RESULTS

Tadalafil dose-dependently inhibited hypernociception in zymosan and osteoarthritis models. In zymosan-induced arthritis, tadalafil significantly decreased cell influx and TNF-α release but did not alter IL-1 or CINC-1 levels. Pretreatment with ODQ but not with naloxone prevented the anti-inflammatory effects of tadalafil.

CONCLUSIONS AND IMPLICATIONS

Therapeutic oral administration of tadalafil provided analgesia mediated by guanylyl cyclase and was independent of the release of endogenous opioids. This effect of tadalafil was associated with a decrease in neutrophil influx and TNF-α release in inflamed joints.

The Major Glycoprotein Allergen from Arachis hypogaea, Ara h 1, Is a Ligand of Dendritic Cell-Specific ICAM-Grabbing Nonintegrin and Acts as a Th2 Adjuvant In Vitro

Nonmammalian glycan structures from helminths act as Th2 adjuvants. Some of these structures are also common on plant glycoproteins. We hypothesized that glycan structures present on peanut glycoallergens act as Th2 adjuvants. Peanut Ag (PNAg), but not deglycosylated PNAg, activated monocyte-derived dendritic cells (MDDCs) as measured by MHC/costimulatory molecule up-regulation, and by their ability to drive T cell proliferation. Furthermore, PNAg-activated MDDCs induced 2- to 3-fold more IL-4- and IL-13-secreting Th2 cells than immature or TNF/IL-1-activated MDDCs when cultured with naive CD4+ T cells. Human MDDCs rapidly internalized Ag in a calcium- and glycan-dependent manner consistent with recognition by C-type lectin. Dendritic cell (DC)-specific ICAM-grabbing nonintegrin (DC-SIGN) (CD209) was shown to recognize PNAg by enhanced uptake in transfected cell lines. To identify the DC-SIGN ligand from unfractionated PNAg, we expressed the extracellular portion of DC-SIGN as an Fc-fusion protein and used it to immunoprecipitate PNAg. A single glycoprotein was pulled down in a calcium-dependent manner, and its identity as Ara h 1 was proven by immunolabeling and mass spectrometry. Purified Ara h 1 was found to be sufficient for the induction of MDDCs that prime Th2-skewed T cell responses. Both PNAg and purified Ara h 1 induced Erk 1/2 phosphorylation of MDDCs, consistent with previous reports on the effect of Th2 adjuvants on DCs.

A quantitative approach to measure joint pain in experimental osteoarthritis--evidence of a role for nitric oxide

OBJECTIVES

To describe a method to study joint pain in experimental osteoarthritis (OA) and to study nitric oxide (NO) participation in experimental OA.

DESIGN

Rats were subjected to anterior cruciate ligament transection (ACLT) (OA group) of the right knee and evaluated during 28 days. A sham group was false operated and a naive group received no manipulation. Joint pain was measured by recording the time the right hind paw fails to touch the surface while walking. Cell influx (CI) and nitrite levels were measured in joint exudates. Expression of inducible NO synthase (iNOS) in synovia was detected by immunostaining. For the specific purpose of pharmacological manipulation, groups received either indomethacin (2 mg/kg/day s.c. (subcutaneous)), meloxicam (6 mg/kg/day s.c.), morphine (200 microg intra-articularly), the non-selective NOS inhibitor L-N(G)-nitroarginine methyl ester (L-NAME; 30 mg/kg/bid i.p. (intra-peritoneal)) or the selective iNOS inhibitor 1400W (0.5 mg/kg/day s.c.), given 30 min prior (prophylactic) or 4 days after (therapeutic) ACLT, until sacrifice, at 7 days. The respective non-treated groups received the vehicles.

RESULTS

The OA group developed joint pain, as compared to sham and control groups (P<0.05). Significantly increased nitrite levels and iNOS immunostaining were seen in the OA group. Both indomethacin and meloxicam inhibited joint pain (P<0.05). Morphine inhibited joint pain, whereas this effect was blocked by co-administration of the mu-opioid receptor naloxone. CI was similar among all groups. Prophylactic but not therapeutic L-NAME or 1400W reduced joint pain.

CONCLUSION

We describe a method to quantitate joint pain associated to weight bearing in the ACLT model. The joint pain is sensitive to classical antinociceptive compounds. NO release is associated to joint pain though NOS inhibition does not inhibit ongoing pain.

Evaluation of the passive particle agglutination test in the serodiagnosis and follow-up of syphilis

We performed the present study to determine the rate of concordance of the fluorescent treponemal antibody absorption test (FTA-ABS) and of the microhemagglutination assay for antibodies to Treponema pallidum (MHA-TP) with the passive particle agglutination test (TP.PA) in patients with early syphilis and to observe the reactivity of the rapid plasma reagin (RPR), MHA-TP, and the TP.PA tests for 1 year after therapy. The study included 449 people who were given therapy if they had syphilis and followed up for 1 year. The rate of concordance of the TP.PA with the MHA-TP was 98.4%, and it was 98.9% with the FTA-ABS. During follow-up, a significant decrease of antibodies was found in 56%, 26%, and 70% of the patients when using the RPR, the MHA-TP, and the TP.PA, respectively. The TP.PA seems to be an adequate routine assay for the diagnosis of syphilis, being as sensitive as the FTA-ABS test in primary syphilis and as useful as the RPR test in monitoring therapy.

Reduction of QTc interval dispersion. Potential mechanism of cardiac protection of pyridostigmine bromide

OBJECTIVE

Parasympathetic dysfunction is an independent risk factor in individuals with coronary artery disease, and cholinergic stimulation is a potential therapeutical option. We determined the effects of pyridostigmine bromide, a reversible anticholinesterase agent, on electrocardiographic variables of healthy individuals.

METHODS

We carried out a cross-sectional, double blind, randomized, placebo-controlled study. We obtained electrocardiographic tracings in 12 simultaneous leads of 10 healthy young individuals at rest before and after oral administration of 45 mg of pyridostigmine or placebo.

RESULTS

Pyridostigmine increased RR intervals (before: 886+/-27 ms vs. after: 1054+/-37 ms) and decreased QTc dispersion (before: 72+/-9 ms vs. after: 45+/-3 ms), without changing other electrocardiographic variables (PR segment, QT interval, QTc, and QT dispersion).

CONCLUSION

Bradycardia and the reduction in QTc dispersion induced by pyridostigmine may effectively represent a protective mechanism if these results can be reproduced in individuals with cardiovascular diseases.

Band ligation or sclerotherapy as endoscopic treatment for oesophageal varices in schistosomotic patients: results of a randomized study

Endoscopic sclerotherapy and banding ligation are the two preferred methods to treat oesophageal variceal bleeding. There are many reports dealing with such treatment in cirrhotic patients but we do not know how good they are to treat varices secondary to other forms of portal hypertension. Schistosomiasis mansoni is the main cause of portal hypertension and oesophageal varices in Brazil. We performed a prospective randomised study to compare: 1) the efficacy of both treatments in eradicating oesophageal varices, and 2) complications secondary to both treatments. Forty patients were divided in two groups. Both sclerotherapy and banding ligation were performed until variceal eradication. There were no severe complications. Variceal eradication was faster obtained with banding ligation than sclerotherapy although there was no statistical difference (mean number of sessions 3.05 vs 3.72, p = 0.053). Benign complications were equally frequent in both groups, although additional sedation was more common in the sclerotherapy group. We concluded that both treatments are equally effective in the eradication of oesophageal varices, although banding ligation is better tolerated by the patient and probably faster.

[Comparison between invasive tests for the diagnosis of Helicobacter pylori infections]

Helicobacter pylori is a Gram negative bacteria that colonizes gastric epithelial cells. It has been associated with several gastric disease including chronic gastritis and peptic ulcer. Helicobacter pylori infection diagnosis can be done with invasive and non-invasive methods. In invasive methods an endoscopic gastric mucosa biopsy specimen is used. In our study we compare the sensitivity, specificity, costs and applicability of four invasive diagnostic tests: culture, urease ultra-rapid test, histology (Giemsa and Hematoxilineosin stain) and fuchsin stained mucosal slides. Urease test was the easiest, fastest diagnostic test, with sensitivity of 86% and specificity of 100%, being also the cheapest test. We concluded that it should be the test of choice for Helicobacter pylori infection diagnosis.

Prospective study of bacteremia rate after elastic band ligation and sclerotherapy of esophageal varices in patients with hepatosplenic schistosomiasis

BACKGROUND

Esophageal band ligation is considered to be as efficient as endoscopic sclerotherapy, with a lower complication rate, including bacteremia. There are few studies comparing the two methods. The aim of this study was to compare the incidence of bacteremia after both treatments in patients with portal hypertension secondary to schistosomiasis.

METHODS

Endoscopic sclerotherapy and band ligation were performed using standard techniques. Blood samples were obtained 5 and 30 minutes after endoscopic band ligation or sclerotherapy and cultured for aerobic and anaerobic organisms.

RESULTS

In the sclerotherapy group 2 of 43 (4.6%) blood cultures were positive (Peptostreptococcus sp and Streptococcus mitis). A similar result was obtained in the band ligation group: 2 of 35 (5.7%) had positive cultures, both with Staphylococcus aureus.

CONCLUSIONS

There is no difference in the frequency of bacteremia after treatment of esophageal varices with endoscopic sclerotherapy or endoscopic band ligation in patients with portal hypertension secondary to schistosomiasis.

Biliary and pancreatic stent blockage by bacterial biofilm: presentation of two cases

Biliary and pancreatic stents are effective tools in the management of obstructive jaundice (both malignant and benign), pancreatic pseudocyst drainage, and as treatment for biliary and pancreatic fistulae. Unfortunately, stents may become blocked and require replacement in a number of patients. In the present study a blocked stent from a patient with transpapillary drainage of pancreatic pseudocyst and another from a patient with obstructive jaundice resulting from cancer of the head of the pancreas associated with Mirizzi syndrome were characterized by electron microscopy. Stent blockage was diagnosed by a pressure test and stent cultures were performed. Electron microscopy of the blocked stents revealed the sludge to consist of microcolonies of bacteria mixed with amorphous material, and cultures of both stents were positive for Klebsiella sp and E. coli.

[Endoscopic therapy of pancreatic pseudocyst]

Endoscopy therapy of pancreatic pseudocyst has been described as an efficient method. We report six cases of pancreatic pseudocyst treated by pancreatic stenting (three cases), cystogastrostomy (three cases) and cystoduodenostomy (one case). Rapid symptomatic improvement and pseudocyst regression were noted in all cases, except one. Such patient needed pancreatic stenting even after cystogastrostomy due to main pancreatic duct stenosis. There were three complications: hemorrhage (one case) and pseudocyst infection (two cases), and all were treated clinically. Two patients had pseudocyst infection previous to endoscopic manipulation, and they were treated only with antibiotics and endoscopic drainage, without surgery (treatment suggested by most of the authors). We concluded that endoscopic therapy of pancreatic pseudocyst is efficient and safe, being responsible for rapid relief of symptoms in most of patients.

[Peutz-Jeghers syndrome and adenocarcinoma. Report of a case]

Peutz-Jeghers syndrome is a rare disease, characterized by autosomic inheritance, presenting skin stain and hamartomatous polyps. We report one case of Peutz-Jeghers syndrome and duodenal adenocarcinoma in a young male who presented with liver metastasis and pancreatic invasion. Such association is reported to be presented in 5% of patients with the syndrome. The reasons of such association are unknown, being possible that: 1) there is malignant degeneration of a adenomatous polyp; 2) malignant degeneration of a hamartomatous polyp, or 3) adenomatous portion of a hamartomatous polyp could undergo malignant transformation.