Peripheral interactions between cannabinoid and opioid systems contribute to the antinociceptive effect of crotalphine.

BACKGROUND AND PURPOSE: Crotalphine is an antinociceptive peptide that, despite its opioid-like activity, does not induce some of the characteristic side effects of opioids, and its amino acid sequence has no homology to any known opioid peptide. Here, we evaluated the involvement of the peripheral cannabinoid system in the crotalphine effect and its interaction with the opioid system. EXPERIMENTAL APPROACH: Hyperalgesia was evaluated using the rat paw pressure test. Involvement of the cannabinoid system was determined using a selective cannabinoid receptor antagonist. Cannabinoid and opioid receptor activation were evaluated in paw slices by immunofluorescence assays using conformation state-sensitive antibodies. The release of endogenous opioid peptides from skin tissue was measured using a commercial enzyme immunoassay (EIA). KEY RESULTS: Both p.o. (0.008-1.0 µg·kg(-1) ) and intraplantar (0.0006 µg per paw) administration of crotalphine induced antinociception in PGE2 -induced hyperalgesia. Antinociception by p.o. crotalphine (1 µg·kg(-1) ) was blocked by AM630 (50 µg per paw), a CB2 receptor antagonist, and by antiserum anti-dynorphin A (1 µg per paw). Immunoassay studies confirmed that crotalphine increased the activation of both κ-opioid (51.7%) and CB2 (28.5%) receptors in paw tissue. The local release of dynorphin A from paw skin was confirmed by in vitro EIA and blocked by AM630. CONCLUSIONS AND IMPLICATIONS: Crotalphine-induced antinociception involves peripheral CB2 cannabinoid receptors and local release of dynorphin A, which is dependent on CB2 receptor activation. These results enhance our understanding of the mechanisms involved in the peripheral effect of crotalphine, as well as the interaction between the opioid and cannabinoid systems.

Periodontal disease and oral health-related behavior as factors associated with preterm birth: a case-control study in south-eastern Brazil.

BACKGROUND AND OBJECTIVE: Several studies have suggested a link between periodontal disease and preterm birth, but the mechanism of how this occurs remains controversial. Therefore, this study aimed to investigate whether periodontal disease, defined according to two commonly used clinical definitions, is associated with preterm birth and to examine the association regarding oral health-related behaviors during pregnancy. MATERIAL AND METHODS: This case-control study included women 18-40 years of age. Demographic and socio-economic data, information on current and previous pregnancies, and data on dental health-related behaviors and periodontal clinical parameters were collected within 48 h postpartum. Periodontal disease was assessed according to two definitions: four or more teeth with at least one site showing a probing depth of ≥ 4 mm and clinical attachment level of ≥ 3 mm (Definition 1); or at least one site with probing depth and clinical attachment level of ≥ 4 mm (Definition 2). The chi-square test was used to examine differences in the proportion of categorical variables. Bivariate analysis was performed to analyze the proportion of preterm births with respect to independent variables. Multiple logistic regression analyses were used to assess the association between periodontal disease and preterm birth. Odds ratios (ORs) were calculated with a 95% confidence interval (95% CI). RESULTS: A total of 296 postpartum women met the inclusion criteria. The case group included 74 women who delivered a preterm neonate (< 37 wk of gestation) and the control group included 222 women with deliveries at term (≥ 37 wk). Periodontal disease according to Definition 1 was not associated with fewer weeks of gestation (adjusted OR (OR adjusted ) = 1.62; 95% CI = 0.80-3.29; p = 0.178). However, a significant association was found between periodontal disease, according to Definition 2, and preterm birth (OR adjusted = 1.98; 95% CI = 1.14-3.43; p = 0.015). Increased appetite and a low number of daily toothbrushings were associated with preterm birth, regardless of the definition of periodontal disease used. CONCLUSION: Periodontal disease defined according to Definition 2 and unfavorable oral health-related behavior were factors associated with preterm birth.

Cytokine profile and FVIII inhibitors development in haemophilia A.

Haemophilia A is a hereditary bleeding disorder linked to the X chromosome characterized by a deficiency or defect in the coagulation factor VIII (FVIII). Individuals with this coagulopathy require constant infusions of FVIII to maintain their physical integrity and haemostasis. During treatment, some patients develop an immune response that produces antibodies to FVIII, also called inhibitors, affecting the pro-coagulant activity of this protein. Despite the clinical relevance of FVIII inhibitors, the immune mechanisms that lead to their production are not known. This study investigated the immunological cytokine profile using plasma from HA patients which were either positive or negative for FVIII inhibitors and from healthy individuals. The results showed that healthy individuals and HA patients that do not develop FVIII inhibitors have a mixed immune response profile with high secretion of IFN-γ, TNF-α IL-2 and IL-5. In contrast, HA patients with FVIII inhibitors exhibited an anti-inflammatory/regulatory immune response characterized by low levels of all measured cytokines except for IL-4 and IL-10. This profile may be related to the development and maintenance of the FVIII inhibitors. By comparing the cytokine profiles of the three different groups we have established a model explaining the immune activation resulting in the production of FVIII inhibitors in haemophilia A patients.

Occurrence of Leishmania donovani parasitemia in plasma of infected hamsters.

Intracardiac transfusion of plasma, mononuclear cell fraction and blood of infected hamster donors induced visceral leishmaniasis in normal hamster receptors. At the moment of transfusion, the donors already showed all the typical signs of the disease: ascites, cachexia, as well as splenomegaly and a high parasite load in the spleen and liver. All transfused hamsters developed typical visceral leishmaniasis between 90 and 120 days, indicating that all blood products were infectious. Transfusion of the mononuclear cell fraction induced the highest values of parasitic load (spleen, 766 Leishman Donovan Units (LDU); liver, 2650 LDU), splenomegaly and hepatomegaly (spleen-liver/body relative weight: 1.130 and 6.870, respectively). Animals that received the plasma fraction also developed visceral leishmaniasis, showing similar parasitic load (spleen, 107 LDU; liver, 220 LDU) and spleen-liver/body relative weight (1.005 and 6.35, respectively) than those transfused with whole blood. The finding of typical Leishmania donovani infection in animals transfused with plasma demonstrates the possibility of the extracellular location of parasites, free in this blood fraction deprived of red and white blood cells. Fluorescence-assisted cell sorter analysis (FACS) of plasma showed the presence of particles corresponding in size to amastigotes, which fluoresced strongly with the serum of a patient with Kala-azar (73%), but not with normal serum.

[Hemostatic and structural effects of the lyophilized cellulose sponge]. / Efeitos hemostático e estrutural da esponja de celulose liofilizada.

Hemostatic effects of oxidized cellulose (Surgicel) are well known. Based on a possible similar effect of a sponge obtained after lyophilization of biosynthetic cellulose, two different experimental studies were planned. Phase I-Pieces of cellulose sponge were inserted into small provoked cortical wounds of twelve dogs. The time elapsed to obtain bloodstill after cortical damage and application of cellulose was observed in every dog, searching to detect any possible hemostatic effect of the material. The animals were sacrificed after 7, 30 and 90 days. An average time of 1 minute was elapsed until bleeding control was achieved. No clinical adverse effect was noticed. Microscopy showed histiocytic and mild foreign body reaction at 7 days, which diminished at 30 days. Almost no reaction surrounded the implant at 90 days. Lyophilized cellulose has a peculiar eosinophilic appearance, composed by thin irregular filaments which diminished their thickness with the time. At 90 days only sparse irregular cellulose filaments could be detected. Phase II-Small equal sponge fragments were inserted in the liver of twelve rats and observed 7, 30 and 90 days. At autopsy, small peritoneal adhesions were noticed at 30 and 90 days. Microscopy showed intense histioplasmocytic and foreign body reaction in all animals mainly at 7 days. In two animals, refringent intracellular cellulose particles were evident inside giant foreign body cells after 90 days. This fact evidences that cellulose can be reabsorbed by phagocytic phenomena when implanted in mammalians. A comparative group with other hemostatic material and the same method must be done to clarify the issue of hemostatic effects of this membrane.

Prevalence of anti-Leishmania donovani antibody among Brazilian blood donors and multiply transfused hemodialysis patients.

The prevalence of anti-Leishmania donovani antibodies was investigated in 1,500 Brazilian blood donors and multiply transfused hemodialysis patients. Sera were tested using the fucose-mannose ligand (FML) ELISA, which was shown to have 100% sensitivity and 96% specificity for kala-azar. Among 1,194 volunteer blood donors, seroreactivity was 9%, increasing to 25% in a periurban kala-azar focus. However, higher positivity (37%) was found in multiply transfused hemodialysis patients from Natal, where kala-azar is constantly present in low numbers (endemic), with sporadic outbreaks in localized regions (endemic and epidemic). Risk factors included blood transfusion, which was significantly associated with the presence of anti-Leishmania antibodies (chi2 = 8.567, P < 0.005), but did not include potential exposure to sandfly bites (chi2 = 0.033, P > 0.1). The prevalence significantly decreased to 7% in hemodialysis patients from Rio de Janeiro, where kala-azar is only occasionally seen, and was 0% in patients undergoing continuous ambulatorial peritoneal dialysis. The prospective analysis of 27 FML-seroreactive donors from Natal revealed amastigotes of Leishmania in the bone marrow of one subject while four had clinical complaints, including splenomegaly and hepatosplenomegaly. Our results point to the need for control of blood transfusion as a possible route for transmission of kala-azar in endemic areas.

Transmission of visceral leishmaniasis by blood transfusion in hamsters.

We have studied the transmission of visceral leishmaniasis by blood transfusion in the CB hamster model. Five normal CB hamsters (females, 2.5 months old) received a 0.1-ml blood transfusion from a donor that had been infected with 10(7) amastigotes of Leishmania donovani 90 days prior to the blood harvest. The development of the disease in transfused animals was monitored by the increase in anti-Leishmania serum antibodies, splenomegaly, and spleen and liver parasitic burdens. The transfused hamsters developed all the typical signs of the disease, i.e., ascites, cachexia and death. The scores of anti-Leishmania antibodies (1.345) and the level of parasite load (spleen Leishman Donovan units of Stauber (LDU) = 471, liver LDU = 378) in transfuse hamsters were similar to those observed in hamsters experimentally infected with 10(7) amastigotes (P > 0.05, Student t-test). Our results demonstrate that blood transfusion is an effective route for transmission of visceral leishmaniasis, and we point out that adequate precautions should be taken at blood banks in the regions where leishmaniasis is endemic.

Transmission of visceral leishmaniasis by blood transfusion in hamsters

We have studied the transmission of visceral leishmaniasis by blood transfusion in the CB hamster model. Five normal CB hamsters (females 2.5 months old) received a 0.1 -ml blood transfusion from a donor that had been infected with 10(7) amastigotes of Leishmania donovani 90 days prior to the blood harvest. The development of the disease in transfused animals was monitored by the increase in anti-Leishmania serum antibodies, splenomegaly, and spleen and liver parasitic burdens. The transfused hamsters developed all the typical signs of the disease, i.e., ascites, cachexia and death. The scores of anti-Leishmania antibodies (1.345) and the level of parasite load (spleen Leishman Donovan units of Stauber (LDU) = 471, liver LDU = 378) in transfused hamsters were similar to those observed in hamsters experimentally infected with 10(7) amastigotes (P>0.05, Student t-test). Our results demonstrate that blood transfusion is an effective route for transmission of visceral leishmaniasis, and we point out that adequate precautions should be taken at blood banks in the regions where leishmaniasis in endemic.

Metal complexes of anhydrotetracycline. 2. Absorption and circular dichroism study of Mg(II), Al(III), and Fe(III) complexes. Possible influence of the Mg(II) complex on the toxic side effects of tetracycline.

Anhydrotetracycline (AHTC) is the major toxic decomposition product of the antibiotic tetracycline. The complexation of AHTC to Mg(II), Al(III), and Fe(III) was studied in aqueous medium using absorption and circular dichroism measurements. The study of the Mg(II)-AHTC interactions at pH 7 indicated the formation of the MHL and M2L species in which an Mg(II) ion is coordinated to the C11 and C12 oxygens of the BCD ring system. In the M2L species, a second metal ion coordinates to the N4 and O3 positions on ring A, inducing the ligand to adopt the "twisted" conformation. At pH 4, an MHL species is formed with Al(III) by complexation of the metal ion to O11 and O12. At pH 1, Fe(III) forms an MH2L species, probably by coordination of the metal to 012 and 01. The stability constants of all species were calculated. The possible participation of Mg(II) in the mechanism of toxicity of tetracycline is suggested.