Human Placenta-Derived Mesenchymal Stem Cells Improve Neurological Function in Rats with Intrauterine Hypoxic-Ischaemic Encephalopathy by Reducing Apoptosis and Inflammatory Reactions.

BACKGROUND: Hypoxic-ischaemic encephalopathy (HIE) is a major cause of neonatal disability and mortality. Although hypothermia therapy offers some neuroprotection, the recovery of neurological function is limited. Therefore, new synergistic therapies are necessary to improve the prognosis. Mesenchymal stem cell-based therapy is emerging as a promising treatment option for HIE. In this study, we studied the therapeutic efficacy of human placenta-derived mesenchymal stem cells (PD-MSCs) in the HIE rat model and analyzed the underlying therapeutic mechanisms. METHODS: Rats were divided into 6 groups (n = 9 for each) as follows: control, HIE model, HIE + normal saline, and HIE + PD-MSC transplantation at days 7, 14 and 28 postpartum. Following PD-MSC transplantation, neurological behavior was evaluated using rotarod tests, traction tests, and the Morris water maze test. The degree of brain tissue damage was assessed by histological examination and Nissl staining. Expression levels of apoptosis-related proteins and inflammatory factors were quantified by Western blotting and enzyme-linked immunosorbent assays. Immunofluorescence was used to investigate the ability of PD-MSCs to repair the morphology and function of hippocampal neurons with hypoxic-ischaemic (HI) injury. RESULTS: PD-MSC transplantation enhanced motor coordination and muscle strength in HIE rats. This treatment also improved spatial memory ability by repairing pathological damage and preventing the loss of neurons in the cerebral cortex. The most effective treatment was observed in the HIE + PD-MSC transplantation at day 7 group. Expression levels of microtubule-associated protein-2 (MAP-2), B-cell lymphoma-2 (BCL-2), interleukin (IL)-10, and transforming growth factor (TGF -ß1) were significantly higher in the HIE + PD-MSC treatment groups compared to the HIE group, whereas the levels of BCL-2-associated X protein (BAX), BCL-2-associated agonist of cell death (BAD), IL-1ß and tumour necrosis factor α (TNF-α) were significantly lower. CONCLUSIONS: We demonstrated that intravenous injection of PD-MSC at 7, 14 and 28 days after intrauterine HI damage in a rat model could improve learning, memory, and motor function, possibly by inhibiting apoptosis and inflammatory damage. These findings indicate that autologous PD-MSC therapy could have potential application for the treatment of HIE.

[Analysis of the changes in bacterial types and drug sensitivity profiles of mycobacterial strains in Guangzhou over the last twelve years].

OBJECTIVE: To improve evidence-based care in the management of tuberculosis, we retrospectively analyzed the bacterial types and drug sensitivity test results of mycobacteria in Guangzhou over the past twelve years (from July 1998 to March 2010). METHODS: Over these twelve years, a total of 14 095 mycobacterial strains isolated from different samples were subjected to type identification and drug sensitivity tests according to the Standard Protocols of Laboratory Diagnostics for Tuberculosis by the Chinese Antituberculosis Association. Chi-square test was performed for statistical analyses for comparisons between groups. RESULTS: Of 14 095 strains of mycobacteria isolated, 10 844 strains (76.84%) were MTB, and 3251 strains (23.16%) were non-tuberculosis mycobacteria (NTM). Compared with the result of the fourth national survey of tuberculosis epidemiology, which showed 11.1% of NTM, the one of our study was significantly different (χ(2) = 69.79, P < 0.001). Drug sensitivity tests of MTB showed tolerance rates of 28.99% (2729/9413), 21.75% (2047/9413), 17.45% (1643/9413) and 11.53% (1085/9413) against isoniazid, rifampin, streptomycin and ethambutol, respectively. CONCLUSION: An increasing trend was observed in MTB drug tolerance against streptomycin, rifampin and isoniazid, whereas more and more NTM strains were isolated in recent years. These findings are worthy of note for clinicians.

Use of visual loop-mediated isotheral amplification of rimM sequence for rapid detection of Mycobacterium tuberculosis and Mycobacterium bovis.

Mycobacterium tuberculosis and Mycobacterium bovis are pathogenic bacterial species in the genus Mycobacterium and the causative agents of most cases of tuberculosis (TB). Detection of M. tuberculosis and M. bovis using conventional culture- and biochemical-based assays is time-consuming and laborious. Therefore, a simple and sensitive method for rapid detection has been anxiously awaited. In the present study, a visual loop-mediated isothermal amplification (LAMP) assay was designed from the rimM (encoding 16S rRNA-processing protein) gene sequence and used to rapidly detect M. tuberculosis and M. bovis from clinical samples in South China. The visual LAMP reaction was performed by adding calcein and manganous ion, allowing the results to be read by simple visual observation of color change in a closed-tube system, and which takes less than 1 h at 65 degrees C. The assay correctly identified 84 M. tuberculosis isolates, 3 M. bovis strains and 1 M. bovis BCG samples, but did not detect 51 non-tuberculous mycobacteria (NTM) isolates and 8 other bacterial species. Sensitivity of this assay for detection of genomic DNA was 1 pg. Specific amplification was confirmed by the ladder-like pattern of gel electrophoresis and restriction enzyme HhaI digestion. The assay successfully detected M. tuberculosis and M. bovis not only in pure bacterial culture but also in clinical samples of sputum, pleural fluid and blood. The speed, specificity, sensitivity of the rimM LAMP, the lack of a need for expensive equipment, and the visual readout show great potential for clinical detection of M. tuberculosis and M. bovis.

Molecular characterization of drug-resistant Mycobacterium tuberculosis isolates in Guangdong, China.

The aim of this study was to characterize 160 clinical Mycobacterium tuberculosis isolates from Guangdong with respect to their drug susceptibility phenotypes to three common anti-tuberculosis drugs, isoniazid (INH), rifampin (RIF) and streptomycin (SM), and with respect to genetic mutations in the most commonly corresponding resistance genes (katG, rpoB and rpsL). The drug susceptibility profiles were evaluated by the absolute concentration method, and genetic mutations in the corresponding resistance genes were identified by DNA sequencing. Among these isolates, 33.1% (53/160) were drug-resistant. The percentages of isolates resistant to INH, RIF and SM were 21.9% (35/160), 16.9% (27/160) and 15.6% (25/160), respectively. Twenty-five of 35 (71%) INH-resistant isolates, 22 of 27 (81.5%) RIF-resistant isolates and 19 of 25 (76%) SM-resistant isolates were found to have mutations in the analyzed katG, rpoB and rpsL gene fragments. The most frequent mutation patterns for the three drugs were as follows: INH, Ser315Thr (68.6%) in katG; RIF, Ser531Leu (55.6%) in rpoB; and SM, Lys43Arg (72%) in rpsL. These findings provide useful data on the mutation types of drug-resistant genes in M. tuberculosis isolates from Guangdong province in China.

[Effects of glucocorticoids on tuberculous pleural effusion: experiment with rats].

OBJECTIVE: To explore the effects of systemic glucocorticoid treatment on tuberculous pleural effusion. METHODS: Ninety Wistar rats were intrapleurally injected with 0.03 mg of standard human Mycobacterium tuberculosis to establish models of tuberculous pleural effusions and then were randomly divided into 2 equal groups both without anti-tuberculosis treatment: glucocorticoids group (GG) undergoing intramuscular injection of 0.3 mg triamcinolone acetonide in the right thigh 24 h after intrapleural injection, and control group (CG) received nothing as control. 8, 24, 32, and 48 hours, and 3, 5, 7, 10, and 15 days after intramuscular injection 5 rats from each group were killed. The thorax was opened, the amount of pleural effusion (PE) was recorded, and the pleural cavity, histopathology of pleura and lung parenchyma were examined. The white blood cell (WBC) count and differential leukocyte count, and levels of total protein (TP), glucose (GLU), and lactic dehydrogenase (LDH) in the PE were determined. Bioassays were used to detect the PE levels of soluble intercellular adhesion molecule-1 (sICAM-1), transforming growth factor beta1 (TGF-beta1), and interferon gamma (IFN-gamma). RESULTS: The PE volumes of GG 8 - 48 h after the intramuscular injection were significantly lower than those of CG (P < 0.05, P < 0.01), and PE completely disappeared on day 3. The WBC in PE 24 - 48 h after and the percentages of neutrophils 8 - 48 h after the intramuscular injection of GG were all significant lower than those of CG (all P < 0.01). The TP levels 32 and 48 h after the intramuscular injection of GG were both significantly higher than those of CG (both P < 0.01). The LDH level of GG within 24 h after the intramuscular injection was significantly lower than that of CG (P < 0.01). Both the sICAM-1 and TGF-beta1 levels of GG were higher 8 h after the intramuscular injection, but lower 48 h after the intramuscular injection than those of CG (both P < 0.01). The IFN-gamma levels 8 - 48 h after the intramuscular injection of GG were all higher than those of CC (all P < 0.01). The IFN-gamma/TGF-beta1 ratios at different time points of GG were all higher than those of CG, and there were significant differences in those 8 - 48 h after the intramuscular injection between these 2 groups (all P < 0.01). Pathologically, the mean thickness of pleura in GG was significantly less than that in CG. Congestion and edema in subpleural and pulmonary interstitium were less in GG than in CG. CONCLUSION: Early use of glucocorticoids helps reduce the inflammatory response in pleural cavity in tuberculous pleurisy accelerate the absorption of pleural effusion and decrease the thickness of pleura.