Sildenafil enhances the peripheral antinociceptive effect of ellagic acid in the rat formalin test

Objective:

Ellagic acid (EA), a major polyphenolic compound of pomegranate juice, produces antinociceptive effects, which are mediated through opioidergic and nitric oxide-cyclic guanosine monophosphate (NO-cGMP) pathways. The present study was conducted to elucidate the peripheral antinociceptive effect of EA alone and in combination with sildenafil in the rat formalin test.

Materials and Methods:

Pain was produced by intraplantar injection of formalin (2.5%) in rats and nociceptive behavior was measured as the number of flinches every 5 min in 60 min after injection.

Results:

Local administration of EA and sildenafil dose-dependently increased the nociception threshold in both phases of the test. Moreover, sub-effective doses of sildenafil (25 or 50 mcg/paw, i.p.) significantly and dose-dependently enhanced the antinociception induced by a sub-effective dose of EA (60 mcg/paw, i.pl.) in both phases of the test. The antinociception produced by these drugs alone, or in combination, was due to a peripheral site of action, since the administration in the contralateral paw was ineffective.

Conclusion:

Our results suggest that EA has local peripheral antinociceptive activity, and enhancement of this effect with sildenafil probably occurs through the inhibition of cGMP metabolism.KEY WORDS: Ellagic acid, formalin, peripheral antinociception, sildenafil     

Normative Data and Psychometric Properties of the Child Behavior Checklist and Teacher Rating Form in an Iranian Community Sample

Objective

The objective of this study was to determine the normative data and psychometric properties of the parent and teacher rating form of the child behavior checklist (CBCL) in an Iranian community sample.

Methods

A sample of 6-12 year old students was randomly selected from ten elementary schools in Tehran, Iran. The parent''s and teacher''s versions of CBCL were accomplished. Clinical interview and the kiddie schedule for affective disorders and schizophrenia – present and lifetime version, Persian version (K-SADS-PL-PV) were used to evaluate the validity and the cut-off point of CBCL and the teacher rating form (TRF).

Findings

Among 600 recruited students with mean age of 9.11 years (SD=1.45), 54.16% were girls (n=325). Girls had significantly lower scores in Attention Problems, Delinquent Behavior, Aggressive Behavior, Externalizing and Total Problems than boys (P<0.01). The relation was significant between the CBCL Internalizing and students'' ages (β=0.124, P=0.002). The Internal consistency, the correlation among the CBCL and TRF scales, and the inter-rater correlations for CBCL/TRF scales were good to high for most indices and subscales. Based on the receiver operating characteristics (ROC) analysis the best convergences were between the CBCL Attention Problems subscale and attention deficit hyperactivity disorder (ADHD) diagnosis, the CBCL Total Problems and any disorders, the CBCL Externalizing and ADHD+ODD diagnosis. The sensitivities and specificities of the CBCL subscales were higher than the TRF except for Externalizing/ADHD+ oppositional defiant disorder (ODD) which was reverse.

Conclusion

These results support the multicultural CBCL/TRF findings. CBCL is a useful instrument to consider ADHD and any disorders in community samples.     

Study of Biofilm Formation in C57Bl/6J Mice by Clinical Isolates of Helicobacter pylori

Background/Aim:

Despite the significant number of studies on H. pylori pathogenesis, not much data has been published concerning its ability to form biofilm in the host stomach. This study aims to evaluate the potential of clinical isolates of H. pylori to form biofilm in C57BL/6J mice model.

Materials and Methods:

Two strains of H. pylori were selected from a collection of clinical isolates; one (19B), an efficient biofilm producer and the other (4B), with weak biofilm-forming ability. Mice infected through gastric avages were examined after one and two weeks. Colonization was determined by CFU and urease activity; the anti-H. pylori IgA was measured by ELISA, and chronic infections were evaluated by histopathology. Bacterial communities within mucosal sections were studied by immunofluorescence and scanning electron microscopy (SEM).

Results:

Successful infection was obtained by both test strains. Strain 19B with higher ability to form biofilm in vitro also showed a higher colonization rate in the mice stomach one week after infection. Difference (P < 0.05) in IgA titers was observed between the infected mice and the controls as well as between 19B and 4B infected mice, two weeks after the last challenge. Immunofluorescence and SEM results showed tightly colonizing H. pylori in stomach mucosal sections and in squamous and glandular epithelium.

Conclusion:

H. pylori is able to form biofilm in the mouse stomach and induce IgA production, reflecting the same potential as in humans. Firm attachment of coccoid form bacteria to host cells suggests the importance of this state in biofilm formation by H. pylori. Occurrence of biofilm in squamous and glandular epithelium of the mouse stomach proposes that H. pylori can all parts of the upper gastrointestinal tract.     

Bladder outlet physiology in the context of lower urinary tract dysfunction

Physiological function of the bladder outlet is complex and symptomatic consequences can result from outlet dysfunction. Within the outlet, smooth, and skeletal muscles constitute the contractile apparatus, but additional cell types include interstitial cells and neuroendocrine cells, and various transmitters are present in the innervation, raising the possibility of unrecognized functional subtleties. Key outlet functions are; maintained closure for urine storage, increased closure (guarding) during exertion, sustained opening for voiding, transient opening for territorial marking in animals and orthograde male ejaculation. These are co-ordinated by several spinal and higher CNS centers, with overlap of the somatic, sympathetic and parasympathetic nervous systems. During voiding, urethral afferents may be important in maintaining detrusor contraction until completion of bladder emptying. Some of the bladder outlet afferents may be shared with the anal sphincter. Dysfunction of the outlet leads to conditions such as retrograde ejaculation, Fowler's syndrome, and detrusor sphincter dyssynergia. Urethral relaxation during urine storage may lead to urinary urgency, which may be misleadingly labeled as overactive bladder. Research priorities are numerous, including; peripheral cellular integrative physiology, interactions with other pelvic organs, interconnectivity of the CNS centers at all levels of the neuraxis, and standardized animal models of outlet functions such as reflex-driven voiding.     

Effect of ultrasonication with EDTA or MTAD on smear layer, debris and erosion scores

The purpose of this study was to compare the effects of ultrasonication with ethylenediaminetetraacetic acid (EDTA) and a mixture of tetracycline isomer, an acid, and a detergent (MTAD) as final canal irrigants on the smear layer, debris and erosion scores. Fifty-eight extracted single-rooted human teeth were instrumented with ProTaper rotary files up to size F3. According to the final irrigation regimen, the samples were distributed into the following groups: EDTA, MTAD, EDTA ultrasonicated for 1 min, and MTAD ultrasonicated for 1 min. The smear layer, debris and erosion scores were recorded at the apical, middle, and coronal third of each canal using a scanning electron microscope. Data were subjected to statistical evaluation using the Kruskal-Wallis and Mann-Whitney tests (P < 0.05). There were no significant differences in smear layer or debris removal between the experimental groups. EDTA caused significantly more erosion at the middle level than MTAD. Also EDTA resulted in more erosion at the coronal level than MTAD when subjected to ultrasonication. Ultrasonic activation of EDTA significantly increased its erosive effects at the middle and coronal levels. Based on the present findings, MTAD appears to cause less dentinal erosion while allowing proper removal of the smear layer and debris.