Ursolic acid and oleanolic acid suppress preneoplastic lesions induced by 1,2-dimethylhydrazine in rat colon

Ursolic acid (UA) and oleanolic acid (OA) are pentacyclic triterpenoid compounds found in plants used in the human diet and in medicinal herbs, in the form of aglycones or as the free acid. These compounds are known for their hepatoprotective, anti-inflammatory, antimicrobial, hypoglycemic, antimutagenic, antioxidant, and antifertility activities. In the present study, we evaluated the effects of UA and OA on the formation of 1,2-dimethyl-hydrazine (DMH)-induced aberrant crypt foci (ACF) in the colon of the male Wistar rat. The animals received subcutaneous (sc) injections of DMH (40 mg/kg body weight) twice a week for two weeks to induce ACF. UA, OA and a mixture of UA and OA were administered to the rats five times a week for four weeks by gavage at doses of 25 mg/kg body weight/day each, during and after DMH treatment. All animals were sacrificed in week 5 for the evaluation of ACF. The results showed a significant reduction in the frequency of ACF in the group treated with the triterpenoid compounds plus DMH when compared to those treated with DMH alone, suggesting that UA and OA suppress the formation of ACF and have a protective effect against colon carcinogenesis.     

Morphological and Autoradiographic Studies on the Corneal and Limbal Epithelium of Rabbits

The investigation was centered on the morphological features of the conjunctiva–cornea transition (limbus) of the rabbit eye and the proliferative behavior of its epithelium. The eyes were processed for examination with light and electron microscopy, as well as for autoradiography after intravitreal injection of [³H]thymidine ([³H]TdR). At the sites of extraocular muscle insertion, the vascularization of the stroma extended to the peripheral cornea, and the limbal epithelium was thin with its basal stratum made up by clear cuboidal cells. In between the muscle insertions, the cuboidal clear cells, as well as the stroma blood vessels, were scarce. At the light microscope level, the basement membrane was distinct in the cornea but not in the limbus or the conjunctiva. Autoradiographs demonstrated that, at the limbus, the basal cells migrated very quickly to the suprabasal region and remained there up to the 28‐day interval. Labeled cells were identified in all epithelial layers of the cornea, including the basal one, at 21 and 28 days but not in the limbal basal clear cells. The rate of renewal of conjunctival epithelium was similar to that observed for the transition with scarce clear cells. The high‐resolution autoradiographs demonstrated that the basal cuboidal clear limbal cells exhibit a quick renewal and that they are not label‐retaining cells. These latter ones were detected all over the corneal epithelium and in the suprabasal layers of the limbus up to 28 days, in physiological conditions, without the need of stimulation by damage to the corneal epithelium. Anat Rec, 291:191–203, 2008. © 2008 Wiley‐Liss, Inc.     

Interaction between immunoglobulin allotypes and NK receptor genes in diabetes post-hepatitis C virus infection

Genetic interactions between natural killer (NK) cells immunoglobulin-like receptor (KIR) genes and immunoglobulin allotypes have been previously reported in type 2 diabetes mellitus (DM) patients. Puerto Rican Americans with a history of intravenous drug use who developed DM following HCV infection (n = 32) were compared to individuals infected with HCV without diabetes (n = 121) and to DM non-infected individuals (n = 95). Subjects were genotyped for KIRs and immunoglobulin allotypes. We found interactions of immunoglobulin allotypes KM3/KM3 with NK inhibitory receptors 2DL3/2DL3, 2DL1 in the absence of 2DS4 associated with susceptibility to DM in HCV infected individuals. These data suggest the possibility that a subset of patients with HCV could have an immune-mediated component contributing to the development of DM.     

Role of quercetin in preventing thioacetamide-induced liver injury in rats

In hepatic toxicity induced in rats by two injections of thioacetamide (TAA, 350 mg/kg with an interval of 8 hr), the action of quercetin was investigated. After 96 hr, TAA administration resulted in hepatic necrosis, significant increases in serum transaminase activity, and increases in hepatic lipoperoxidation. Thioacetamide-induced hepatotoxicity also showed changes in antioxidant enzymes in the liver of rats, with alterations in p-ERK 1/2 (phosphorylated extracellular-signal related kinase 1/2) as well as an imbalance between proapototic protein Bax and anti-apoptotic protein Bcl-2 expression. With administration of the flavonoid quercetin (50 mg/Kg i.p.) for four consecutive days following TAA, serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activity were close to normal values in rats. Histological findings suggested that quercetin had a preventive effect on TAA-induced hepatic necrosis. Quercetin treatment caused significant decreases in lipid peroxide levels in the TAA-treated rats, with some changes in antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx). Quercetin also inhibited the change of the p-ERK1/2 by TAA and significantly prevented the increase in Bax/Bcl-2 ratio, thus preventing apoptosis. Findings indicate that quercetin may have a preventive effect on TAA-induced hepatotoxicity by modulating the oxidative stress parameters and apoptosis pathway.     

Interleukin-1 receptor-associated kinase 4 is essential for initial host control of Brucella abortus infection

Brucella abortus is a facultative intracellular bacterial pathogen that causes abortion in domestic animals and undulant fever in humans. Recent studies have revealed that Toll-like receptor (TLR)-initiated immune response to Brucella spp. depends on myeloid differentiation factor 88 (MyD88) signaling. Therefore, we decided to study the role of the interleukin-1 receptor-associated kinase 4 (IRAK-4) in host innate immune response against B. abortus. After Brucella infection, it was shown that the number of CFU in IRAK-4(-/-) mice was high compared to that in IRAK-4(+/-) animals only at 1 week postinfection. At 3 and 6 weeks postinfection, IRAK-4(-/-) mice were able to control the infection similarly to heterozygous animals. Furthermore, the type 1 cytokine profile was evaluated. IRAK-4(-/-) mice showed lower production of systemic interleukin-12 (IL-12) and gamma interferon (IFN-γ). Additionally, a reduced percentage of CD4(+) and CD8(+) T cells expressing IFN-γ was observed compared to IRAK-4(+/-). Further, the production of IL-12 and tumor necrosis factor alpha (TNF-α) by macrophages and dendritic cells from IRAK-4(-/-) mice was abolished at 24 h after stimulation with B. abortus. To investigate the role of IRAK-4 in mitogen-activated protein kinase (MAPK) and NF-κB signaling pathways, macrophages were stimulated with B. abortus, and the signaling components were analyzed by protein phosphorylation. Extracellular signal-regulated kinase 1 (ERK1) and ERK2 and p38 as well as p65 NF-κB phosphorylation was profoundly impaired in IRAK-4(-/-) and MyD88(-/-) macrophages activated by Brucella. In summary, the results shown in this study demonstrated that IRAK-4 is critical to trigger the initial immune response against B. abortus but not at later phases of infection.     

Direct analysis of genetic variability in Trypanosoma cruzi populations from tissues of Colombian chagasic patients

The clinical symptoms of Chagas disease are highly variable and are correlated with geographical distribution and parasite genetic group. Trypanosoma cruzi group I is associated with chagasic cardiomyopathy in Colombia and other countries in northern South America. However, in southern South America, T cruzi group II predominates and is associated with cardiomyopathy and digestive forms of the disease. The aim of this work was to determine the correlation between the genetic profiles of T cruzi groups circulating in the biological cycle and those present in tissues from patients with Chagas disease. We genotyped T cruzi in 10 heart tissue samples from patients with cardiomyopathy from a highly endemic area of Colombia. The genotyping was performed using nuclear and mitochondrial genes and low-stringency single-specific primer polymerase chain reaction. As expected, the predominant genetic group was T cruzi group I; however, we also detected T cruzi group II. Microsatellite analyses suggested a predominance of monoclonal populations, and sequence alignments showed similarities with Colombian strains. In addition, kinetoplast DNA signatures obtained by low-stringency single-specific primer polymerase chain reaction allowed us to group strains into the 2 genetic groups. Thus, we conclude that both T cruzi genetic groups are producing severe cases of Chagas disease in Colombia. We did not observe any correlation between low-stringency single-specific primer polymerase chain reaction profiles, histopathologic findings, clinical forms, and severity of Chagas disease.     

Heel quantitative ultrasound parameters in subjects with the metabolic syndrome: the Camargo Cohort Study

Objectives

To compare bone parameters measured by calcaneous quantitative ultrasonography (BUS) in subjects with and without metabolic syndrome (MetS). In addition, we wanted to examine the association of each of the individual components of the syndrome with BUS measurements, to study the relationship between calciotropic hormones or bone turnover markers with BUS parameters in subjects with or without MetS, and to explore the possibility that the relationship between prevalent vertebral and non-vertebral fractures and BUS is influenced by MetS status.

Study design

Cross-sectional study.

Results

We investigated 1209 (421 men and 788 women) participants from the Camargo Cohort Study. Prevalence of MetS was 27% in men and 31% in women. Women, but not men, with MetS had higher age-adjusted BUS parameters compared with those without (p < 0.05), the difference disappearing after adjustment for BMI. Out of the five single components of MetS, only waist perimeter was significantly associated with BUS (p < 0.01), the association being restricted to women. In men and women with MetS (but not without) a positive significant association was observed between BUS and 25OHD levels. BUS parameters were associated with serum P1NP or CTX in normal women, but not in those with MetS. Prevalent vertebral and non-vertebral fractures and BUS parameters (BUA and SOS, respectively) are inversely associated, but this relationship, however, is not influenced by MetS status.

Conclusions

BUS parameters are higher in women with MetS, and this difference disappears after adjusting for BMI. MetS status did not influence the relationship between BUS parameters and vertebral or non-vertebral fractures.     

Outcome of children hospitalized with community-acquired pneumonia treated with aqueous penicillin G

OBJECTIVE:

To describe the evolution and outcome of children hospitalized with community‐acquired pneumonia receiving penicillin .

METHODS:

A search was carried out for all hospitalized community‐acquired pneumonia cases in a 37‐month period. Inclusion criteria comprised age ≥2 months, intravenous penicillin G use at 200,000 IU/kg/day for ≥48 h and chest x‐ray results. Confounders leading to exclusion included underlying debilitating or chronic pulmonary illnesses, nosocomial pneumonia or transference to another hospital. Pneumonia was confirmed if a pulmonary infiltrate or pleural effusion was described by an independent radiologist blind to the clinical information. Data on admission and evolution were entered on a standardized form.

RESULTS:

Of 154 studied cases, 123 (80%) and 40 (26%) had pulmonary infiltrate or pleural effusion, respectively. Penicilli was substituted by other antibiotics in 28 (18%) patients, in whom the sole significant decrease was in the frequency of tachypnea from the first to the second day of treatment (86% vs. 50%, p = 0.008). Among patients treated exclusively with penicillin G, fever (46% vs. 26%, p = 0.002), tachypnea (74% vs. 59%, p = 0.003), chest indrawing (29% vs. 13%, p<0.001) and nasal flaring (10% vs. 1.6%, p = 0.001) frequencies significantly decreased from admission to the first day of treatment. Patients treated with other antimicrobial agents stayed longer in the hospital than those treated solely with penicillin G (16±6 vs. 8±4 days, p<0.001, mean difference (95% confidence interval) 8 (6–10)). None of the studied patients died.

CONCLUSION:

Penicillin G successfully treated 82% (126/154) of the study group and improvement was marked on the first day of treatment.     

No evidence of association of the KLF12 gene with rheumatoid arthritis in Spanish and Dutch cohorts and a meta-analysis of published data

The aim of the present study was to replicate the previously reported association of KLF12 gene polymorphisms with rheumatoid arthritis (RA). Two independent cohorts from Spain (1,360 RA patients and 1,520 controls) and the Netherlands (1,018 RA patients and 1,150 controls) were genotyped for KLF12 rs1887346 and rs9565072 single-nucleotide polymorphisms using a TaqMan 5'-allele discrimination assay. No evidence of association of RA with the minor T allele of rs9565072 (31.82% vs 33.73%; p = 0.14, odds ratios [OR] 0.92 [95% confidence interval (CI) 0.82-1.03]) or the minor A allele of rs1887346 polymorphism (21.60% vs 21.77%; p = 0.88, OR 0.99 [95% CI 0.87-1.13]) was observed in Spanish patients compared with healthy controls. This lack of association was also confirmed in the Dutch cohort: the minor T allele frequency of rs9565072 in Dutch RA patients was 35.34% versus 35.57% in controls; p = 0.87, OR 0.99 (95% CI 0.87-1.12); and the minor A allele frequency of rs1887346 in Dutch RA patients was 27.64% versus 28.17% in controls; p = 0.70, OR 0.97 (95% CI 0.85-1.12). A meta-analysis of published KLF12 gene association with RA revealed a pooled OR of 0.99 (95% CI 0.93-1.04) for rs1887346 and a pooled OR of 0.99 (95% CI 0.95-1.04) for rs9565072. In conclusion, our findings indicate that the KLF12 rs1887346 and rs9565072 polymorphisms do not play a relevant role in RA.     

Distribution and identity of neurons expressing the oxytocin receptor in the mouse spinal cord

Nurr1 is a member of the nuclear receptor superfamily and is a regulatory factor of differentiation, migration and maturation of mesencephalic dopaminergic neurons. The present study was designed to observe the dynamic changes in the protein expression of Nurr1 and the relationship between Nurr1 and proliferating cell nuclear antigen (PCNA) during rat brain and spinal cord development. And we also investigated the significance of Nurr1 in differentiation and migration of nerve cells. Paraffin-embedded sections, immunohistochemistry, immunohistochemical double staining and Western blot techniques were used. The results demonstrate that the presence of Nurr1-positive cells increased during embryo development and that these cells slowly migrated to locations far from the lateral ventricle. In postnatal rats, the presence of Nurr1-positive cells surrounding the lateral ventricle decreased markedly. The expression of Nurr1 in the cerebral cortex peaked at postnatal days 1-5 (P1-P5) and then decreased as the cells matured, becoming rare in the mature cerebral cortex. As the cells matured, a staircase-shaped migration of Nurr1-positive cells from dorsal areas to ventral areas of the spinal cord could be observed. As maturation continued, the presence of Nurr1-positive cells in the spinal cord decreased, and no Nurr1-positive cells were found in the mature spinal cord. The comparative observation of Nurr1 and PCNA showed that the two proteins were expressed in different regions and in different cells. Nurr1 was confined to differentiated and migrating immature cells and was not present in proliferating cells. We suggest that Nurr1 may play a regulatory role in the differentiation, migration and maturation of nerve cells in the rat brain and spinal cord.