Rectal swab sampling followed by an enrichment culture-based real-time PCR assay to detect Salmonella enterocolitis in children.

Although routine bacterial culture is the traditional reference standard method for the detection of Salmonella infection in children with diarrhoea, it is a time-consuming procedure that usually only gives results after 3-4 days. Some molecular detection methods can improve the turn-around time to within 24 h, but these methods are not applied directly from stool or rectal swab specimens as routine diagnostic methods for the detection of gastrointestinal pathogens. In this study, we tested the feasibility of a bacterial enrichment culture-based real-time PCR assay method for detecting and screening for diarrhoea in children caused by Salmonella. Our results showed that the minimum real-time PCR assay time required to detect enriched bacterial culture from a swab was 3 h. In all children with suspected Salmonella diarrhoea, the enrichment culture-based real-time PCR achieved 85.4% sensitivity and 98.1% specificity, as compared with the 53.7% sensitivity and 100% specificity of detection with the routine bacterial culture method. We suggest that rectal swab sampling followed by enrichment culture-based real-time PCR is suitable as a rapid method for detecting and screening for Salmonella in paediatric patients.

Molecular and immunocytochemical identification of coxsackievirus A-24 variant from the acute haemorrhagic conjunctivitis outbreak in Taiwan in 2007.

AIMS: Acute haemorrhagic conjunctivitis (AHC) is a highly contagious conjunctivitis associated with enteroviruses. Coxsackie A-24 variant (CA-24v) and enterovirus-70 (EV-70) are the two major causative agents. During October 2007, an epidemic of AHC occurred in Taiwan, affecting more than 11 000 people. The aim of this study was to determine the aetiological agent associated with the outbreak in patients diagnosed with AHC and treated at the Cathay General Hospital, Taipei (CGHT) and Cathay General Hospital Sijhih (CGHS), Taiwan during October 2007. METHODS: Virus isolates were obtained from six patients (four from CGHS and two from CGH), and a total of seven specimens (one throat and one rectal, and five eye swabs) were collected. The specimens were inoculated onto the MRC-5 cell lines. The viral isolation was confirmed by performing real-time reverse transcription-polymerase chain reaction (RT-PCR) and indirect immunofluorescence assay (IFA). RESULTS: The conjunctival, throat, and rectal swabs collected in this study were all tested positive for a variant of CA-24. All seven viral isolates were characterized as a variant of CA-24 and confirmed by IFA and real-time RT-PCR. CONCLUSIONS: The findings suggest that the outbreak of AHC that occurred during October 2007 in the northern area of Taiwan was caused by a variant of coxsackie A-24. Further phylogenic analysis is underway to further classify this CA-24v strain.

The quantitative analysis of peripheral blood FOXP3-expressing T cells in systemic lupus erythematosus and rheumatoid arthritis patients.

BACKGROUND: Expressed in naturally occurring CD4+CD25+ regulatory T cells, FoxP3 plays an important role in maintaining immune tolerance. We therefore evaluated the possibility that the peripheral blood FOXP3+ T-cell deficiency is associated with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). MATERIALS AND METHODS: The FOXP3 expression in peripheral blood T cells were evaluated and correlated to the CD4 and CD25 expression by flow cytometric analysis. Cell frequencies of FOXP3+ T cells among CD4+ T cells and absolute FOXP3+ T cell counts in SLE and RA patients were determined for the statistical comparison with those in normal controls, and their correlation with disease activities in SLE patients was evaluated. The FOXP3 transcript levels in peripheral blood mononuclear cells (PBMCs) were also determined to correlate the FOXP3+ T-cell quantity and to evaluate the possible dysregulation in the expression of two FOXP3 mRNA variants in patients. RESULTS: SLE patients had the higher FOXP3+ T-cell frequency and absolute CD4+CD25-FOXP3+ cell count than normal individuals, and the frequencies of CD4+CD25+FOXP3+ and CD4+FOXP3+ cells were positively correlated with the disease activities in SLE patients. In contrast, the differences in frequencies and absolute counts of FOXP3+ T cells between normal controls and RA patients were found to be insignificant. Moreover, SLE and RA patients appear to express two FOXP3 transcript variants in peripheral blood mononuclear cells at the levels similar to normal individuals. CONCLUSIONS: The peripheral blood FOXP3+ T-cell frequency among CD4+ T cells is altered in SLE patients with the active disease activity. Therefore, the analysis on peripheral blood FOXP3+ T cells may be useful for the evaluation of lupus disease activity.

The pattern and distribution of calcitonin gene-related peptide (CGRP) terminals in the rat dorsal following neonatal peripheral inflammation.

Neonatal peripheral inflammation has been shown to alter the neural circuitry of the spinal cord in adult rats. However, the temporal and spatial changes in the distribution of primary afferent terminals immediately following a neonatal inflammatory stimulus remains unclear. In the present study we found that intraplantar injection of complete Freund's adjuvant (CFA) or saline alone on postnatal day 1 (P1) causes CGRP immunoreactivity (CGRP-Ir) to gradually increase from P6 to P15 in laminae I and II, and return to baseline at P22. In laminae III and IV, CGRP-Ir markedly increased beginning at P6, and remained elevated thereafter. CGRP-Ir in lamina V remained unchanged throughout the observation period. These findings show that intraplantar CFA induces CGRP-fiber sprouting in laminae III and IV, but not in laminae I, II or V. We suggest that neonatal inflammation causes changes in the neural circuitry pattern in various regions of the dorsal horn during the critical neonatal development period in rats.

Increased Fos induction in adult rats that experienced neonatal peripheral inflammation.

The response to noxious stimulation was compared in adult rats that had peripheral inflammation as neonates and untreated rats. On postnatal day 1, rat pups experienced complete Freund's adjuvant (CFA)-induced inflammation of the left hind paw. At 8 weeks of age, these rats and neonatal untreated rats received a bilateral injection of CFA into their hind paws. Fos-like immunoreactivity (Fos-LI) was used as a measure of neuronal activity in dorsal horn nociceptive pathways. A significant increase in Fos-LI was found on the left side of the lumbar spinal cord of neonatal treated rats as compared to neonatal untreated rats. These results suggest that the experience of neonatal peripheral inflammation may result in an increase in the response of spinal cord neurons to peripheral inflammation as adults.

Altered nociceptive neuronal circuits after neonatal peripheral inflammation.

Nociceptive neuronal circuits are formed during embryonic and postnatal times when painful stimuli are normally absent or limited. Today, medical procedures for neonates with health risks can involve tissue injury and pain for which the long-term effects are unknown. To investigate the impact of neonatal tissue injury and pain on development of nociceptive neuronal circuitry, we used an animal model of persistent hind paw peripheral inflammation. We found that, as adults, these animals exhibited spinal neuronal circuits with increased input and segmental changes in nociceptive primary afferent axons and altered responses to sensory stimulation.

An electron microscopic study of the processes of nerve regeneration after lyophilized nerve homografting.

The objective of the present study was to investigate the role of the Schwann cell basal lamina in nerve regeneration. To achieve this goal, we observed the process of axonal regeneration within a lyophilized nerve graft, in which only the basal lamina of the Schwann cell persisted. Sciatic nerves were removed from rats and lyophilized to kill the Schwann cells and other components. These grafts were transplanted to rat sciatic nerve defects. The rats were then killed after lapses of time. We observed the processes of axonal regeneration using a transmission electron microscope. Regeneration of axons along the inner surface of the Schwann cell basal lamina was clearly seen. These results suggest that, if tubular basal laminae persist, Schwann cells are not always necessary, and axonal regeneration can be induced in the direction toward the basal lamina.